Does your engine sound exactly like this when cold(read post first)?

montreal · Post by **montreal** » Thu Apr 14, 2005 2:59 am

Initial Post starts after following consolidated statistics, as of Dec 9, 2006Poll resultsCorolland .............Yes= 2...............No= 21...........Yes,but different sound= 2MatrixOwners...........Yes= 9...............No= 52...........Yes,but different sound= 1GenVibe................Yes= 11...............No= 34...........Yes,but different sound= 0ToyotaNation-Corolla...Yes= 4...............No= 26...........Yes,but different sound= 0ToyotaNation-Matrix....Yes= 0...............No= 15...........Yes,but different sound= 1The creator of poll....Yes= 1Total..................Yes= 27..............No= 148..........Yes,but different sound= 4 Grand total = 179Percentage with identical sound = 15.1%Percentage without sound = 82.7%Percentage with different sound = 2.2%While the polls are anonymous, there are posts in all these forums by owners claiming to have the identical issue.For the purpose of identifying which models and production years are involved, they are as follows in no particular order:There are no automatic transmissions among this group.From MATRIXOWNERS.COMMaidkarenD......'03..Matrix.XR......location:IllinoisLime............'03..Matrix.XR......location:OntarioPegMatrix.......'03..Matrix.XR......location:Manitobaoracle (friend).'04..Matrix.XR......location:OntarioPurplenv........'03..Matrix.XR......location:OntarioBridgejoe.......'03..Matrix.........location:Minnesotadominator.......'04..Matrix ........location:OntarioTruckerbob......'03..Matrix.........location:Ontariochmodx..........'05..Matrix.........location:VirginiaTheCrispyness...'04..Matrix.........location:Illinoisdexter..........'03..Matrix.XR......location:OntarioMontreal........'03..Matrix.........location:QuebecOntario member..'03..Matrix.........location:OntarioFrom COROLLAND.COMBobLevine........'03..Corolla......location:North Carolinaeuzeka...........'04..Corolla......location:QuebecTi-Jean (friend).'03..Vibe.........location:Quebecamember..........'03..Corolla......location:QuebecMr.Ed............'04..Corolla......location:?Lethal 7.........'04..Vibe.........location:IllinoisFrom GENVIBE.COMHeh!heh!..........'03..Vibe.........location:Ontariojoatmon...........'03..Vibe.........location:Marylandmartinz...........'03..Vibe.........location:OntarioAndrew-4ce........'03..Vibe.........location:Ontarioburkeyro..........'03..Vibe.........loaction:OhioNeouka............'03..Vibe.........location:Ontariostoutvibe.........'??..Vibe.........location:Minnesotasylvainber........'04..Vibe.........location:IllinoisFrom TOYOTANATION.COM (Corolla)John2000ve........'00..Corolla......location:TexasCorollaULEV.......'03..Corolla......location:VirginiaAUDI..............'03..Corolla......location:Ontariorated_w...........'01..Corolla......location:OntarioFrom TOYOTANATION.COM (Matrix)Salsa03...........'03..Vibe.........location:OntarioOther statsThread HitsCorolland................22676Matrixowners..............6418GenVibe...................5959ToyotaNation-Corolla......2717ToyotaNation-Matrix.......1738Audio recording downloads..1165Links to pollshttp://www.corolland.com/forum...17277http://w ... 9&hl=Links to technical discussion.http://forums.genvibe.com/zerothread?id=9403Listen to the sound recording of my engine and please participate in the poll questions which appear at the end of this post. The recording last 20 seconds and captures an event that typically lasts about 40 seconds. This happens at least once a day in winter since my 2003 Matrix was new. Vibe, Matrix and Corolla use the same engine.Link to shared thread containing MP3 recording, click on attachment at bottom of first post:http://forums.genvibe.com/zerothread?id=20409In another thread titled "Engine surges when very cold", some GENVIBE forum members participated in a discussion aimed at finding a technical solution for a rare characteristic that affected a small number of Vibe, Corolla and Matrix owners in the colder climates of North America.It is only because Toyota head office has recently thrown in the towel that I regretably feel obliged to place my complaint in the public domain. Also, there has been some confusion as to what the sound is really like. I am pleased to offer for the first time ever a sound recording of the event.What we all hoped to eliminate is a unique sound that our engines make during the second minute following a startup after the cars have sat in below freezing temperatures for a minimum of 6 - 8 hours.For the most part, this issue appears to be cosmetic. Neither drivability nor fuel economy are negatively affected. Nor do these cars pollute.Many dealerships have made honest, but unsuccessful, attempts to find a solution.The turning point for me was when I realized that I could pull the fuse on the engine computer and make this sound go away for 2 days at a time. Initially, I concluded that no single engine component was defective, rather that all my engine components behaved in a unique combination so as to challenge my engine computer to its limit in order to properly manage the engine when cold. After several weeks I began to believe that the noise might be the engine's reaction to an air leak or injection leak that takes 2 days for the computer to fully evaluate. If there is a leak, then it is not bad enough to throw a code, but bad enough to create an over-reving situation. The sound you hear is how a computer typically protects against a runaway idle, cutting and resuming fuel once the idle falls below a threshold.If I were Pontiac or Toyota, I would not want to change the multi-million dollar software of their engine computer in order to satisfy a handfull of unlucky owners. Nevertheless, I paid a full price for my new car and did not end up with one that sounds like all the other Toyotas or Vibes in my city. Toyota writes that my car is "not abnormalâ€. But it doesnâ€™t sound normal to me. How about you?Please vote in the poll and post any answers which address the following:1) how objectionable would you find this sound were your car to make it at the same frequency and for the same time duration as mine, and2) if you were offered for sale a second-hand Vibe, Corolla or Matrix that makes this sound, would you offer less money to purchase it, and if so, how much less money, bearing in mind that this issue is strictly cosmetic?Thanks in advance for your participation.

bud_one · Post by **bud_one** » Thu Apr 14, 2005 3:14 am

1) If mine idled like that - I'd find someway to fix it...that would be annoying 2) And if I were to buy a car used that did that I'd offer him $500 bucks lessby the way it sounds like an Idle air control/speed control motor has gone haywire....or the intake sensor has an issue... that's what I'd go after first if it were my car....

montreal · Post by **montreal** » Thu Apr 14, 2005 3:36 am

I have tested the idle air motor in the following ways:1) with a scan tool, I can make it open and close on demand,2) if I unplug it before starting the car while cold, I get the predicted 1200 default position rpms. If I disconnect it after the car is all warmed up, I get the same 1200 rpms.3) this part works perfectly during the 2 days following a ECU memory reset while the ECU is learning all it doesn't like about the engine sensors. The car idles at 1800 rpm and increase 200 rpm with each new trip until the pulsing starts again.After much discussion on several different forums, I was led to the following conclusion:Normally these engines idle initially at 1800 rpm when very cold and drop slowly to 800 over several minutes. For me to be initially idling at 2300 rpm, there must be more energy being consumed than in the normal engine in order to turn the engine parts 25% faster.You can only have 25% more energy if you have 25% more gas AND 25% more oxygen. Increasing air without increasing gas or vice versa will not give us more energy, it will give us an overly lean condition or an overly rich condition.I believe that my ECU is taking 2 days to discover that 25% more air is arriving in the cylinders or 25% more gas is leaking through an injector(s) than the computer expects. Using the oxygen sensor, the ECU arrives at this conclusion and decides what it now has to do during subsequent cold starts where the it doesn't use the oxygen sensor because this sensor takes several minutes to heat up to operating temperature. As a result, I believe that my ECU is either commanding the idle air motor to open 25% more or all the fuel injectors to spray 25% more fuel to compensate for the perceived leak.The alternate theory is that there is no real leak of any kind, only the presence of a group of marginal engine sensors that spook the ECU into believing that the engine cold idle rpm should be raised by 25% to get the car warmed up faster than normal.I prefer the theory about a leak but I am not yet prepared to poke around the plumbing looking for it and my car's manufacturer (while under warranty) does not want to acknowledge that the noise is in anyway related to a defect, either a real one or one imagined by the engine computer.Thanks for your comments.

Raven · Post by **Raven** » Thu Apr 14, 2005 3:38 am

1. I could not stand that noise period.2. I would not buy a car that did that for any price. My friend has a '94 Honda Accord that does the same thing. It was fine until his wife brought it in for a tune-up without asking him(it didn't need one) and it has done it ever since. It must be caused by a bad sensor but it is odd that no trouble codes appear even when scanned at the dealer. Perhaps it is the ECU which is faulty.

montreal · Post by **montreal** » Thu Apr 14, 2005 3:46 am

Three scans were made over 3 weeks last February and there were no codes.When I say 25% more energy is required to turn 25% faster, I am exaggerating for clarity purposes.In fact, because there is no load on the engine while in neutral (mine is a 5 speed), maybe only 5% more energy is required at 2300 rpm than at 1800. Maybe an air leak of 5% above what is normal is not enough for the ECU to throw a code.Nevertheless, the ECU seems pretty upset with an idle of 2300 rpm given the current engine coolant temperature and the volume of fuel being injected.As for the ECU itself being faulty, we have a 'victim' in St-Paul,Mi. who reported on another site that the changing of his computer did not help.Thanks for your response.

esjones · Post by **esjones** » Thu Apr 14, 2005 3:47 am

Quote, originally posted by montreal Â»Listen to the sound recording of my engine and please participate in the poll questions which appear at the end of this post. The recording last 20 seconds and captures an event that typically lasts about 40 seconds. This happens at least once a day in winter since my 2003 Matrix was new. Vibe, Matrix and Corolla use the same engine.That is completely unacceptable! It sounds like the wood chipper in the movie "Fargo!"

montreal · Post by **montreal** » Thu Apr 14, 2005 4:02 am

This noise started the day I bought the car in Feb. 2002. When I described the sound to my dealer, he said many new generation cars with this engine sound that way. It took me 2 years to realize that all my friends with the same engine did not sound that way and I had better get this car inspected before my 3 year warranty expired.Because it only happens after sitting 6 hours in the cold, I had to leave the car overnight at the dealer and then be there the following morning to witness the car performing on queue.I had to repeat this same process a few days later so the dealer could get a scan of the engine. They foolishly changed my O2 sensor (with head office approval) not realizing that O2 sensors , even heated ones, take more than two minutes to warm up from a frozen state.A week later we repeated again and this time I wasn't there to witness. Amazingly the car did not make the noise according to the dealer's mechanic, but given that the car fails on 99 winter days out of 100, I suspect the car had been accidentally started before the scan tool could be attached, thereby voiding the test.I then had the car scanned for the 3rd time at a well known independent garage, where it predictably failed.So unless you actually hear the recording, there are no words to describe this sound that will be perfectly understood by a mechanic. Quote, originally posted by esjones Â»"...sounds like the wood chipper in the movie "Fargo!" I once compared the sound to a donkey braying.If you have ever let your parked lawnmower burn off all its gas at the end of the season before storage, you might have rememered how the speed governor pulses the carborator as it begins to die.

Kari · Post by **Kari** » Thu Apr 14, 2005 4:08 am

Quote, originally posted by montreal Â»This noise started the day I bought the car in Feb. 2002. When I described the sound to my dealer, he said many new generation cars with this engine sound that way.I'm really starting to wonder what's up with the "oh that's normal" attitude many dealers seem to be taking these days. Many of these issues are obviously *not* normal, yours included, but they don't want to bother to dig too deep into trying to figure out what's wrong, so therefore they just write it off as "normal" if they don't anticipate any major adverse consequences at the moment.I've never heard a "new generation car" sound like this. Ever. And I don't think anyone else on the board has had this particular issue either, as would be the case if this was "normal," since many of our members live in colder climates. If this was normal, I doubt you'd be the only one...

bud_one · Post by **bud_one** » Thu Apr 14, 2005 4:13 am

What about the coolant temperature sensor and/or readings at the ecm?The Idle air control gets a signal from that too...An air pocket in the cooling system right at the sensor...?

joatmon · Post by **joatmon** » Thu Apr 14, 2005 4:14 am

My car has the problem of the idle surge when very cold, for maybe the second minute after starting. Usually I start driving before the car warms up, often before it gets a chance to hit the surge cycles, and the erratic idle only lasts for 30-60 seconds, till it starts to warm up some. It's spring here, I likely won't have the problem recur for another seven months or so.I listened to the audio clip, and I hear the idle surge, sounds like someone alternatively pressing and releasing the gas pedal. Is that all that I am supposed to hear, or is there something else about the tone of the engine sound, or perhaps some other abnormal engine sound that is supposed to be odd (other than just the engine revving up and dropping down repeatedly)?

montreal · Post by **montreal** » Thu Apr 14, 2005 4:20 am

Quote, originally posted by KARI Â»I've never heard a "new generation car" sound like this. Ever. And I don't think anyone else on the board has had this particular issue either, as would be the case if this was "normal," since many of our members live in colder climates. If this was normal, I doubt you'd be the only one...I think by new generation, the dealer was recognizing that the cold idle speed of newer cars seems to be faster than a decade ago.While they're saying that this sound is "not abnormal" they are also saying in their e-mail response that they have received no similar complaints.They seem to be placing this sound in the category of squeeks and rattles, where many cars have them (eventually) but that driveability and resale value are not affected.The manufacture does not want to recoginize that the public has a different comfort level when it comes to sqeeks and rattles compared to an engine going into panic mode for 40 seconds each winter morning.P.S. I can't seem to find the control button on this forum that allows me to quote your post.

montreal · Post by **montreal** » Thu Apr 14, 2005 4:31 am

Quote, originally posted by bud_one Â»What about the coolant temperature sensor and/or readings at the ecm?The Idle air control gets a signal from that too...An air pocket in the cooling system right at the sensor...?All these PIDs as they are called had reasonable values and the results of the first 2 scan teats were forwarded to Toyota head office for their consideration. If there was one value out of wack, I think someone would have spotted it.Please remember, I am one of many Toyota and Pontiac owners who have had our mechanics attempt in good faith to find a remedy.Given that all these attempts have failed, many involving the replacement of a variety of sensors, it may be time to conclude that this problem is very unique and does not leave the traditional signatures associated with idle hunting in other types of vehicles.Consider the following links that have gone into the technical aspects of this problem:Links to poll results and comments:http://www.matrixowners.com/fo...38489h ... .htmlLinks to futile discussions of a potential technical solution:http://www.matrixowners.com/fo...34534h ... ad?id=9403

joatmon · Post by **joatmon** » Thu Apr 14, 2005 4:34 am

I can't remember from all those other threads, and I have a stock intake. Does anyone with a CAI have this engine surge problem?Quote, originally posted by montreal Â»P.S. I can't seem to find the control button on this forum that allows me to quote your post.hit the quote button when composing the reply

Attached files

montreal · Post by **montreal** » Thu Apr 14, 2005 4:46 am

Quote, originally posted by joatmon Â» Usually I start driving before the car warms up, often before it gets a chance to hit the surge cycles.I listened to the audio clip, and I hear the idle surge, sounds like someone alternatively pressing and releasing the gas pedal. Is that all that I am supposed to hear, or is there something else about the tone of the engine sound, or perhaps some other abnormal engine sound that is supposed to be odd (other than just the engine revving up and dropping down repeatedly)? If you have a 5 speed and drive away before the first minute has expired and don't come to a stop sign or red light during the second minute, then you will never hear your motor make this sound. But if you are at a stop light during the second minute in neutral, then you will hear this pulsing. Whenever the gas pedal is pressed during the second minute, the motor switches out of idle mode, even if you are still in neutral, and the pulsing stops.As for the recording, there is no abstraction to look for in the sound. The recording is made by placing a microphone (still digital camera) next to the exhaust pipe. Placing the microphone under the hood allows it to pickup noise from the fan belt which removes the clarity.All that one must acknowledge from the sound is that the engine computer alone is responsible for the rpms cycling up and down in that repetitive pattern that lasts about 40 seconds (my 20 second recording is a truncated version of the real 40 second event).There is no person in the car pressing on the gas pedal. In fact you would find it impossible to tap the gas pedal and artificially produce the same noise. That is what is so innocuous about the sound. It is too uniform and highly controlled, by the secret intelligence built into the computer.

montreal · Post by **montreal** » Thu Apr 14, 2005 4:48 am

Quote, originally posted by joatmon Â» Does anyone with a CAI have this engine surge problem?They might if the leak in the CAI is just the right size and they live in a cold climate.This assumes that the surging is the computer's response to a real air leak and not some other software/sensor shortcoming.

montreal · Post by **montreal** » Thu Apr 14, 2005 5:01 am

Quote, originally posted by joatmon Â»My car has the problem of the idle surge when very cold, for maybe the second minute after starting. If your car sounds like mine, then you have the same problem. So far I am the only one to have voted in the poll as having this problem.If you truly have it, then you could bump the counter up to 2 so that we officially record your observation.Thanks

joatmon · Post by **joatmon** » Thu Apr 14, 2005 5:11 am

I voted in the poll, but was waiting to find out if there was some nuance to the sound I needed to match in order to vote for the "exactly" option. I can't swear that mine is "exactly" like yours in every way, but close enough.And, mine doesn't do it lately, because of warmer weather

ToolGuy · Post by **ToolGuy** » Thu Apr 14, 2005 5:20 am

This is a completely stock Trix right?I do not have that problem. However has a dlr hooked it up to a scan tool in front of you and actually watched the engines behavior on the screen? Open loop and closed loop, your car runs in one while cold. You can also observe certain sensors and injector pulses on the tool.Has the dlr reflashed the ECM with newer software?Have you tried another dlr? I use the Tech 2 and it shows what I mentioned above. That would really give a tech an idea of what is going on. No codes have to be present to do this and you are getting none. This is not normal and something is calling for the surges...

montreal · Post by **montreal** » Thu Apr 14, 2005 5:50 am

Quote, originally posted by MiVibe-ToolGuy Â»1)This is a completely stock Trix right?2) has a dlr hooked it up to a scan tool in front of you and actually watched the engines behavior on the screen? 3)Has the dlr reflashed the ECM with newer software?4)Have you tried another dlr? 1) This car has not been modified and the noise started when the car was brand new. Others have reported the same problem on new cars.2) I saw the readout of the first scan in the dealership on his scope. Other than the O2 sensor not outputing during the first 2 minutes (which is expected), all other PIDs looked fine. I was given the opportunity to record PIDs during a third scan and copy them onto paper afterwards. I too could find nothing unusual. One problem is that most scan tools can only fetch a limited number of PIDs within a fixed time. I know that during all three scan tests we did not fetch all the data that is available, only the most popular items.3) Unfortunately there is no newer software because the manufacturer has yet to accept that there is a problem nor to identify if it is sensor or software related.4) I can't go to another dealer without paying, as my 3 year warranty just expired. Also spring is here and I need another 6 months before it would be cold enough to verify any solution. I'm not sure what engine components are covered by the 5 year warranty. Of all the owners with this problem who have posted on this and 4 other internet forums, there is not one who has had a successful remedy. That is why I am reluctant to try another dealer.At this point I feel my best chance is with a buy-back and it is the positive response in this poll and 4 others like it which will help me make a vehicule exchange with no extra penality above a reasonable allowance for depreciation. The salesman seems to be taking his time getting back to me.

montreal · Post by **montreal** » Thu Apr 14, 2005 5:58 am

Quote, originally posted by desert_dweller Â» I would probably offer at least 25%-30% less what you were asking, but probably would not buy it at all. I guess it would depend on how badly I needed a car and how much you were asking.That's the kind of posting I am hoping to get but I also want unbiased responses. Your response appears genuine.Prior to owning this car, I owned a Corolla wagon for 8 years. When I convert the bought and sold price of the Corolla wagon to current dollars as well as the purchase price of my problematic Matrix, I note that I bought both cars for similar amounts and I sold the Corolla wagon after 8 years for 28% of it's original value.If I were to sell you my Matrix after 8 years having the sound that it makes, I'm not sure you would want to give me 28% of the new car cost.Thanks

bud_one · Post by **bud_one** » Thu Apr 14, 2005 6:00 am

Quote, originally posted by MiVibe-ToolGuy Â»Has the dlr reflashed the ECM with newer software?The pcm's on our cars are read only - you cannot reflash them...thus the bulletin on rotten egg smell - replacing the pcm and not just updating it like all the other gm vehicles

tnpartsguy · Post by **tnpartsguy** » Thu Apr 14, 2005 7:06 am

Quote, originally posted by Kari Â»I'm really starting to wonder what's up with the "oh that's normal" attitude many dealers seem to be taking these days. Many of these issues are obviously *not* normal, yours included, but they don't want to bother to dig too deep into trying to figure out what's wrong, so therefore they just write it off as "normal" if they don't anticipate any major adverse consequences at the moment....To be blunt, the reason we can't say anything other than 'oh that's normal' is because GM is aware of all these noises (the entire line of truck engines rattles and knocks on start-up) and because they on a corporate level can't or won't fix them. There are entire websites dedicated to GM's piston-slap problem in the 4.8, 5.3, & 6.0 line of vortex engines, but the only thing GM will admit to is carbon build-up on the piston tops, which is considered "normal". Most of the problems aren't fixable, because even a brand new motor will do it after 20K~50K miles.Trust me, it's not that the dealer doesn't care about this stuff, we just won't get paid to chase engine noises with no known cure.

bud_one · Post by **bud_one** » Thu Apr 14, 2005 7:20 am

so true oh, so true....Quote, originally posted by tnpartsguy Â»Trust me, it's not that the dealer doesn't care about this stuff, we just won't get paid to chase engine noises with no known cure.

scherry2 · Post by **scherry2** » Thu Apr 14, 2005 9:22 am

Quote, originally posted by tnpartsguy Â» we just won't get paid to chase engine noises with no known cure.which is too bad, it isn't like the "old days" pre 80.

ToolGuy · Post by **ToolGuy** » Thu Apr 14, 2005 8:38 pm

You need a good tech to spend time diagnosing it. Sounds like the dlr, unless a check engine light is on and they can just throw a part at it, does not want to spend the time or have a tech spend the time diagnosing it. This is the hard part...Meet with the dlr zone rep and tell them you will be pursuing a buy back if this does not get resolved. For what its worth, from the GM serv manual:Rough, Unstable, or Incorrect Idle and StallingRough, Unstable, or Incorrect Idle, Stalling ChecksAction DEFINITION: The engine runs unevenly at idle. If severe enough, the engine or vehicle may shake. The engine idle speed may vary in RPM. Either condition may be severe enough to stall the engine. The engine idles at an incorrect speed. Preliminary Check â€¢ Refer to Diagnostic System Check - Engine Controls . â€¢ Refer to Symptoms - Engine Controls . Sensor Checks â€¢ Inspect the heated oxygen sensors (HO2S) 1 and HO2S 2 for a condition that can affect sensor activity and response. Refer to Diagnostic Aids for the following DTCs: - DTC P0130 - DTC P0133 - DTC P0135 or P0141 - DTC P0136 â€¢ Inspect the throttle position (TP) sensor. A sticking throttle shaft or a binding throttle linkage will causes a high TP sensor voltage. Under these conditions the powertrain control module (PCM) may not control the idle. Monitor the TP sensor angle with the scan tool. The indicated angle should be approximately 11 percent with the throttle closed. â€¢ Inspect the engine coolant temperature (ECT) sensor. A fixed or inaccurate ECT sensor reading can cause the engine idle to surge or race. Using the scan tool, compare the ECT with the ambient air temperature on a cold engine. If the engine coolant is 5Â°C (9Â°F) more than or 5Â°C (9Â°F) less than the ambient air temperature, inspect the resistance of the coolant sensor. Refer to Temperature vs Resistance . If the ECT is significantly less than the ambient air temperature, inspect the coolant sensor electrical circuit for high resistance. â€¢ Inspect the mass air flow (MAF) sensor operation. Run the engine to normal operating temperature. Turn OFF all accessories and observe the MAF sensor at idle with a scan tool. If the MAF sensor reading is more than 3.5 g/s refer to DTC P0101 . If the MAF sensor reading is less than 1.0 g/s, inspect for a vacuum leak between the MAF sensor and the engine. Fuel System Checks â€¢ Inspect the operation of the fuel system for rich or lean condition. Operate the vehicle under the conditions that caused the concern. Monitor the Fuel Trim parameter on a scan tool in order to identify the problem. - Lean--The Long Term Fuel Trim will be more than 20 percent. Refer to Diagnostic Aids in DTC P0171 . - Rich--The Long Term Fuel Trim will be less than -20 percent. Refer to Diagnostic Aids in DTC P0172 . â€¢ Test the fuel pressure while the condition exists. Refer to Fuel System Diagnosis . â€¢ Inspect the evaporative emission (EVAP) control system. Refer to Electronic Ignition (EI) System Diagnosis . â€¢ Test the fuel injectors for leaking. Refer to Fuel Injector Balance Test with Special Tool . Ignition System Checks â€¢ Test for the proper secondary voltage output with a J 26792 Spark Tester. â€¢ Inspect the spark plugs for correct operation and good ignition system performance. Refer to Spark Plug Inspection . â€¢ Inspect the ignition coil boots for damage. â€¢ Observe the IAC Motor Command parameter on the scan tool at idle, while operating the rear defogger, the A/C system, or the headlights. The IAC Motor Command parameter should increase 2-7 percent when operating the engine loads. If the IAC Motor Command parameter remains fixed, check for a short to ground in the Diagnostic Request circuit from the PCM to terminal 13 of the data link connector (DLC) OBD2. Refer to Engine Controls Schematics . Engine Mechanical Check â€¢ Inspect for the following engine mechanical conditions: - Any faulty hydraulic lifter assemblies - Any broken or weak valve springs - A low compression - An incorrect valve timing - Any sticking or leaking valves - An incorrect or worn camshaft â€¢ Refer to the Diagnostic Starting Point - Engine Mechanical in Engine Mechanical. Additional Checks â€¢ Inspect for vacuum leaks. Vacuum leaks can cause a higher than normal idle speed. â€¢ Verify the PCM grounds are clean, tight, and in the proper locations. Refer to Engine Controls Schematics . â€¢ Check the scan tool to determine if the PCM is receiving an A/C signal. The idle speed should be increased with the A/C ON. Refer to Electrical/Accessory Load Idle-Up Signal Diagnosis . â€¢ Inspect the battery cables and the ground straps. They should be clean and secure. â€¢ Inspect the A/C refrigerant pressure for being too high or for a faulty high pressure switch. Refer to Air Conditioning (A/C) System Performance Test in Heating, Ventilation, and Air Conditioning. â€¢ Test for the proper operation of the IAC system. Refer to Idle Air Control (IAC) System Diagnosis . â€¢ The engine will run rough and the engine can stall if the camshaft position (CMP) actuator solenoid is advancing camshaft timing at idle. Inspect for a fully energized or stuck CMP actuator solenoid. If the operation of the CMP actuator solenoid is suspect, refer to DTC P1349 . â€¢ Inspect the positive crankcase ventilation (PCV) valve for correct operation and the correct part. Refer to Crankcase Ventilation System Inspection/Diagnosis in Engine Mechanical. â€¢ Inspect that the idle speed is increasing for changes in electrical loads on the engine. Refer to Electrical/Accessory Load Idle-Up Signal Diagnosis . â€¢ Verify that the PCM is increasing the idle speed when the P/S system pressure is increased on turns. Refer to Electrical/Accessory Load Idle-Up Signal Diagnosis . â€¢ Inspect for broken or worn motor and transmission mounts.

zionzr2 · Post by **zionzr2** » Fri Apr 15, 2005 1:54 am

I just had this thought .....If you gots a problem and you take it to the dealer and get the "OH that's Normal" speech. Why not make the dealer show you that every other vehicle of same type on the lot does the same thing?

montreal · Post by **montreal** » Fri Apr 15, 2005 1:57 am

Quote, originally posted by MiVibe-ToolGuy Â»1) You need a good tech to spend time diagnosing it. Sounds like the dlr, unless a check engine light is on and they can just throw a part at it, does not want to spend the time or have a tech spend the time diagnosing it.2) Meet with the dlr zone rep and tell them you will be pursuing a buy back if this does not get resolved. 3) For what its worth, from the GM serv manual:Rough, Unstable, or Incorrect Idle and StallingDEFINITION: The engine runs unevenly at idle. If severe enough, the engine or vehicle may shake. The engine idle speed may vary in RPM. Either condition may be severe enough to stall the engine. The engine idles at an incorrect speed.To answer these 3 points:1) The dealer says he would be happy to spend time if I pay him. It is the manufacturer that does not want to cover this under the warranty.2) The salesman who sold me that car asked me to have my car evaluated for a buyback. So far he is 3 days late in getting back to me with his opening offer.3) Of the 4 problems you listed "Rough, Unstable, or Incorrect Idle and Stalling", I have the following two:"Incorrect Idle" mine is 2300, should be like most others, 1800 during first 2 minutes when cold. The second, more frightening problem is not in your list. It is the ECU killing the engine in response to an idle that is too high. Unfortunately the manufacturer does not want to acknowledge that this is the correct reaction by the ECU to an abnormal condition that has been detected by the ECU in spite of no code being thrown. If ever there was such a code to be created to correspond to this condition, it might have the title, "Sensor inputs too confusing for software to resolve".Having such a code logged would be proof positive that there is a defect present in the engine. The message that this code would deliver to the mechanic would be to prepare yourself for a costly fishing expedition to be paid for by the owner or the manufacturer. Since most emission system components are warranted for many years, it would be the manufacturer picking up the tab.Thanks for your very useful list which I may end up personally following if my buyback deal falls through and if the courts don't help me out.

montreal · Post by **montreal** » Fri Apr 15, 2005 2:03 am

Quote, originally posted by zionzr2 Â»I just had this thought .....If you gots a problem and you take it to the dealer and get the "OH that's Normal" speech. Why not make the dealer show you that every other vehicle of same type on the lot does the same thing?The dealer never said that the car was normal. The dealer wrote me back saying that the manufacturer says that the car is "not abnormal".There appears to be a gap between something that is "Normal" and something that is "Not Abnormal".It creates a grey area where judges must decide that in a world where nothing is pure white nor pure black, if I have suffered in an unreasonable way due to this problem, worthy of compensation.That is why the original thread in this forum devoted to finding a technical solution has given way to this new thread devoted to finding a legal solution to what might be a problem which has no practical technical solution.

AKLGT · Post by **AKLGT** » Fri Apr 15, 2005 1:12 pm

Quote, originally posted by montreal Â»They might if the leak in the CAI is just the right size and they live in a cold climate.This assumes that the surging is the computer's response to a real air leak and not some other software/sensor shortcoming.well i have a cai and had mine in all winter. though it surges during idling, it DOES NOT sound like that! something is definitely NOT right!

kostby · Post by **kostby** » Fri Apr 15, 2005 4:26 pm

I had a similar kind of cold idle surging problem on my 1988 Ford Escort GT. (At least it sounded A WHOLE LOT like the clip you posted.)The only computer error code they could get was that the car was running lean. (This was mid-80's computer diagnostics, so I'm not sure how many conditions there were - maybe only 3- 'rich', 'lean', and 'normal'?)After 18 months of fighting with the dealer's service department and a car that was damn near undriveable at times, THEY finally found the problem. The rubber 'hose' (for lack of a better description) that ran between the airflow sensor and the engine intake had a small tear on the underside of it, where it could not be seen.When the car idled, the airflow sensor worked as designed UNTIL the rpms would drop. The ECU called for (I'm guessing) more air and fuel to raise the RPM back up. At that point, THE TEAR IN THE RUBBER HOSE would open and additional air leaked in UPSTREAM of the sensor, hence the lean condition. The sensor obviously couldn't measure the extra air coming in, so the ECU would try to richen the mixture, almost bogging the engine. Idle speed drops, tear in the hose closes... etc. etc.Mashing the throttle to acceleate away from a stop while the engine was cold of course exacerabated the leaking problem, because HUGE amounts of extra air got sucked in, leaning the engine out even more.Hope this helps. As I recall there are rubber parts in the Vibe/Matrix air/fuel system that could be subject to the same type of 'invisible' tear.

montreal · Post by **montreal** » Sat Apr 16, 2005 2:11 am

Quote, originally posted by kostby Â»I had a similar kind of cold idle surging problem on my 1988 Ford Escort GT. (At least it sounded A WHOLE LOT like the clip you posted.)That is good new, it suggests we might have the same problem.Quote, originally posted by kostby Â»The only computer error code they could get was that the car was running lean. (This was mid-80's computer diagnostics, so I'm not sure how many conditions there were - maybe only 3- 'rich', 'lean', and 'normal'?)My car gives no codes, probably because the leak, if there is one, is smaller, perhaps, much smaller.Quote, originally posted by kostby Â»When the car idled, the airflow sensor worked as designed UNTIL the rpms would drop. The ECU called for (I'm guessing) more air and fuel to raise the RPM back up. What would suddenly make the rpms drop? I understand that if the rpms drop, then the ECU should respond by opening the idle air bypass valve and raising the injection simultaneously to increase the rpms, but what would explain a transition from a smooth idle at a fixed rpm to another lower rpm?Quote, originally posted by kostby Â»At that point, THE TEAR IN THE RUBBER HOSE would open and additional air leaked in UPSTREAM( I believe you mean DOWNSTREAM) of the sensor, hence the lean condition. The sensor obviously couldn't measure the extra air coming in, so the ECU would try to richen the mixture, almost bogging the engine. Idle speed drops, tear in the hose closes... etc. etc.I don't think the ECU would try to richen the mixture because if the car is still cold, the O2 sensor would not yet be working to advise of a super lean condition. More likely, the rpms started to fall because of the leaness. But does a super lean mixture necessarily cause a drop in rpms? I received notice last week from a person who builds oxygen sensor simulators and he said that a leanness actually causes a slight increase in rpms. In any case, if the rpms suddenly fall for whatever reason, then it seems reasonable that the tear in the hose could close down.Nevertheless, if the ECU needed to raise the rpms to compensate for falling rpms by opening the idle air bypass valve, then as the rpms increased, so did the vacuum in the intake maniford. As the vacuum went up, then more air was sucked through the tear in the rubber hose. Because this new air was unmeasured, there was not the complementary amount of gas injected, so the mixture went super lean. Then the rpms started to fall naturally (I assume).When the rpms fell below a threshold, the ECU re-opened the air bypass valve and the rpms began to climb, but we started to suck unmetered air again and we were back to the super lean condition.So once the pulsing started, it would have been very difficult to get it to stop unless we waited for the engine to be warm enough to go into closed loop mode, or if we slightly pressed on the accelerator to get the vehicle moving with the help of the injectors now following the TPS instead of the cold idle fixed fuel table.What could be different in the case of the current VIBE/Matrix issue.1)The leak is so small that no code is thrown.2)It takes 2 days for the ECU to recognize the size of the leak and alter the cold idle fuel/bypass air motor trim values.3)The sudden fall in rpms from a peak of 2300 seems to be more likely caused by the ECU deciding that 2300 is too high and ordering a cut, rather than the result of a super lean condition causing the engine to die naturally, as in your case. I believe these 3 difference are making the solution for my car much harder to find, thus I have started directing my energy towards finding a legal solution.Thanks for your thoughtful observations.

Mavrik · Post by **Mavrik** » Sat Apr 16, 2005 3:27 am

My Vibe only sounded like that once... when I installed my Cold Air Intake and messed up my Mass Air Flow Sensor resulting in engine cutting off the fuel supply at 2800rpms. new sensor fixed the problem. Second time I heard that sound was when the engine was cold, I started it up and it was fine, idled fine but after about a minute of driving it began to surge, sounding like the air or fuel was cutting out. After a few moments, it went away... never heard it again and was told by members here that it was normal.I listened to your sound file and something is indeed wrong. If you have not already and this car does this all the time, leave it with the dealer for a cold start so they can experience it if its not doing it right away. They can plug in their computer to the car and read the information showing because that is not right.

montreal · Post by **montreal** » Sat Apr 16, 2005 3:57 am

Quote, originally posted by Mavrik Â»Second time I heard that sound was when the engine was cold, I started it up and it was fine, idled fine but after about a minute of driving it began to surge, sounding like the air or fuel was cutting out. After a few moments, it went away... never heard it again and was told by members here that it was normal.I listened to your sound file and something is indeed wrong. If you have not already and this car does this all the time, leave it with the dealer for a cold start so they can experience it if its not doing it right away. They can plug in their computer to the car and read the information showing because that is not right.The car went to the dealer on three occasions.First time for them to hear it. They did.Second time for them to scan it while the noise was occuring, they did.Third time was for a re-scan after their replacement of the oxygen sensor failed to improve things, they scanned but claimed that the noise did not occur this time. I wasn't there to witness the outdoor procedure on that snowy day.The car then went to an independant garage where they heard the noise and did a scan at the same time and issued me with a document proving that the car still made the noise.Since this car has made this noise on 99 out of 100 winter mornings, I find it hard to believe that it failed to make the noise after being left overnight at the dealer for the second scan. I feel that someone accidentially started or moved the car before the scan tool could be set up outdoors, thereby making the test impossible. The fact that the second scan reportedly did not pick up the event did not help when the manufacturer subsequently decided to cancel all further warranty work.Because the car is and always has been driveable, I can understand that the manufacturer does not see himself as being on the hook in order to come up with a satisfactory solution.The burden of proof is on me to show that this driveable car has lost a real amount of value due to the public's unwillingness to accept a second-hand car that makes a noise like no others.That is why I depend on forum members who respond to my 1 plus 2 question poll to give me the evidence that I need to go to court.Thanks for you suggestion. I hope you voted.

Mavrik · Post by **Mavrik** » Sat Apr 16, 2005 11:58 am

Personally I'd stand out there with a sales person, the tech and the service manager and have all three of them listen to the noise for a few moments and then ask."So... now if I was told it was normal to sound that way all the time, think anyone would buy this?"And then see what they say. Its doing it, there is something wrong, its a problem. Obviously what they did, did NOT fix it. They are not done looking then. Have they called GM Tech support and started a tech case on your car? Have they done anything other then scratch their (removed) and throw a O2 sensor on it? Apparently not. You should not have to take this to court for them to realise. "Seems this isn't right."

montreal · Post by **montreal** » Sat Apr 16, 2005 12:27 pm

Quote, originally posted by Mavrik Â»Personally I'd stand out there with a sales person, the tech and the service manager and have all three of them listen to the noise for a few moments and then ask."So... now if I was told it was normal to sound that way all the time, think anyone would buy this?".The tech who changed the O2 sensor heard it live twice. He knows he didn't fix it.The salesman heard the internet recording. He said that doesn't sound right. He said he would help me out on a buyback, but he said something about reducing my loss, but he never said reduce my loss 100%.The service manager said that people would buy my car because people buy second hand Chrysler minivans where the reputation for fragile transmissions leads to un-driveability and I don't have a driveability problem.The manufacturer has received a copy of the sound recording but apparently doesn't care to answer my e-mails.Quote, originally posted by Mavrik Â»Have they called GM Tech support and started a tech case on your car? You should not have to take this to court for them to realise. "Seems this isn't right."While Vibe and Matrix share the same motor and have the same issue, my car was manufactured by Toyota. Toyota tech support paid about $400 in two failed attempts under warranty to solve this. They have since closed my dossier.Obviously, the top people don't understand the computer program (probably written by a Japonese team), or they understand that there are borderline cases where the computer can barely control the engine. If they make the software intolerant enough to detect whatever is wrong with my engine, they end up with a software that makes the Check Engine Light go on in too many cars. Somewhere they have to draw a line knowing full well that a few hundred customers like myself might end up in a no-man's land where the car can't be fixed and it can't be sold without a loss. That is why some States have lemon laws, because sooner or later, every assembly line produces a lemon. It's the law of statistics. That's why I will probably end up going to court. The burden of proof is on my shoulders.Thanks for stating "Seems this isn't right". I agree.

Mavrik · Post by **Mavrik** » Sat Apr 16, 2005 5:40 pm

Oh sorry right you have a Matrix?Now correct me if I am wrong but your saying since they spent $400 warranty dollors trying to fix but failed to fix the problem, they are NOT going to continue?

Ponyota · Post by **Ponyota** » Sat Apr 16, 2005 7:00 pm

Keep on em about it. Don't let up and don't take no for an answer. Take it all the way to the top if you don't get the satisfaction that your looking for. If you exhaust all your known resources to get it fixed, call your local television station and ask them to do a short news story on lemon laws and have them help you get it fixed. The media sometimes has the power to get things moving when they start shining the spotlight on someone. If worse comes to worse, you can do like a friend of mine did a few years ago. He had a brand new car and they couldn't fix it. He told them after 6 attempts that if they couldn't get it fixed he was going to drive it through the front window of the showroom and leave it there. He did exactly that!

montreal · Post by **montreal** » Sat Apr 16, 2005 9:42 pm

Quote, originally posted by Mavrik Â»Now correct me if I am wrong but your saying since they spent $400 warranty dollars trying to fix but failed to fix the problem, they are NOT going to continue?That's correct. My problem falls into the grey area where the car is very driveable, so it is hard for me to claim distress.It is therefore easy for the manufacturer to claim that the noise is purely cosmetic and not the symptom of a hidden defect. Until I have a high gasoline bill from an overrich motor or burnt valves from an overlean motor, I have no proof that my noise is nothing more than an over cautious engine computer that for some strange reason wants to rush through the cold idle process faster than the average engine.I used to rebuild carburators in the late 1970's so I know what sounds normal. Because I program robots that use technology based on the early NASA space project, I also have to admit that the manufacturer's explanation is plausible.My problem is that it will take at least 8 to 10 years to find out if my car has suffered in any way or if the problem was really cosmetic.People appear to instinctively shy away from buying a car that sounds funny. In the case of this car, their reluctance may not be justified, but if someone has to lose money because of this noise, I believe it should be the manufacturer and not the buyer of a one in a thousand type of vehicle.Hope you voted.

montreal · Post by **montreal** » Sat Apr 16, 2005 10:12 pm

Quote, originally posted by Ponyota Â»....call your local television station and ask them to do a short news story on lemon laws and have them help you get it fixed. The media sometimes has the power to get things moving when they start shining the spotlight on someone. (my friend said he)... was going to drive it through the front window of the showroom and leave it there. He did exactly that!If my luck had been better, I would have a car like the other 98% that work perfectly or the other 1% that work so badly, it is obvious what should be repaired.We have very good lemon laws where I live so I still have many options.Is my car a lemon?What is the definition of a lemon?What if the car drives well but people don't want to purchase a car which sounds funny?People with all sorts of real and cosmetic handicaps bond everyday. But when it comes to assembly line products where everyone pays the same price and expects the same advantage, people go to great lengths to make sure that equality is delivered.I won't drive my car through the showroom window just to make a point. If I could afford this publicity stunt, I would leave my car dangling from a 50 foot crane above a space rented in a downtown parking lot. The public would see a 30 day countdown timer running. On expiry, the car would be dropped onto an armour piercing pointed plate. That would certainly attract a lot of publictiy. Total cost, probably $40K.The truth is the manufacturer is already being embarrassed enough as the results of this and 4 other similar polls.I guess we are both testing where our breaking points are, when it comes to new vehicle warranties.P.S. How much did it cost to replace the showroom window, and who paid?

Ponyota · Post by **Ponyota** » Sat Apr 16, 2005 10:24 pm

Quote, originally posted by montreal Â»P.S. How much did it cost to replace the showroom window, and who paid?I like your idea of how to grab their attention! Hang in there and don't let go. Since your car is drivable, I think they will be the one to crack first. About the window. Well this was a long time ago, but the story went that he was finely given a new car. He paid the damages to both the car he ran through the window and the window itself. I was thinking at the time it was around 2k.

joatmon · Post by **joatmon** » Sun Apr 17, 2005 7:34 am

I don't plan on selling my car for a long time, and by the time I do, it's reasale value will be fairly negligible, so the cold idle surge prob isn't going to affect the resale value of mine.If some unforseen circumstance came up where I really did need to sell it, I would try to wait for warmer weather. If that wasn't an option, I'd reset the ECU every other day. Might not be saintly honest, but what the hell, the car manufacturer has ceretified that the problem is "not abnormal". I'd even tell a buyer it's supposed to do that as a way of heating up faster.The problem doesn't seem to have affected my fuel efficiency or engine performance, just a bit odd idle for a short time when it's really cold, and I'm way past warrranty. I am not going to put much, if any effort into getting it resolved. I might think about it again in December.

montreal · Post by **montreal** » Sun Apr 17, 2005 9:47 am

Quote, originally posted by joatmon Â»I don't plan on selling my car for a long time, and by the time I do, it's reasale value will be fairly negligible, so the cold idle surge prob isn't going to affect the resale value of mine.The problem doesn't seem to have affected my fuel efficiency or engine performance, just a bit odd idle for a short time when it's really cold, and I'm way past warrranty. I am not going to put much, if any effort into getting it resolved. I might think about it again in December.Matrix and Vibe have the potential of only depreciating 0.75% per month, so your car may still be worth more down the road than you expect.It indeed may be nothing more than the computer trying to warm the car up faster and not realizing that the process might trigger the over-rev protection routine.Since we are the only two owners to have checked off the "Yes" option on the poll, you will get a PM from me should ever I be informed of a remedy. So far all I have to go on is the suggestion that it might be a minor air leak in the vacuum hoses.Both the Vibe and Matrix were introduced in the spring of 2002, so I'm wondering how you can be way past the three year warranty, unless your car is neither of these two model, in which case I would be very interested in knowing what model and year it is.

joatmon · Post by **joatmon** » Sun Apr 17, 2005 10:06 am

The Pontiac warrnaty on Vibes is for three years, or 36,000 miles, whichever comes first. I bought my Vibe on December 30, 2002, and hit 36,000 miles on Feb 3, 2004. I currently have 77K miles on it. The rate I put miles on the car made the three year option irrelevant. If I figure out a solution, I will be sure to let you know, but it won't be before next winter that I will experience the problem again and will have an opportunity to troubleshoot.

montreal · Post by **montreal** » Mon Apr 18, 2005 12:23 am

Regarding MiVibe-ToolGuy instant message to me about using a smoke machine instead of propane to diagnose vacuum leaks, here is my response which is too large for an instant message:The use of smoke dilutes the mixture but does not change the ratio as detected by the O2 sensor. The EGR valve has the same effect, it introduces gases that have already been burnt so there is neither oxygen nor unburnt hydrocarbons being added to the normal mixture. This extra inert gas that the EGR allows to enter the cylinder along with the fresh mix of gas and oxygen will have the effect of lowering the peak combustion temperature and reduce the NO2. But will this extra dilution actually cause the rpms to drop (stumble)? I'm not sure. Without hearing the motor suddenly change cadence when your smoke machine passes over an air leak, it would be hard to know which hose connection is faulty. On the other hand, the use of propane allows the oxygen entering via the air leak to be suddenly replaced with propane. That causes an immediate change in the (monitored) oxygen sensor voltage and perhaps a sudden drop in the idle rpms because we are reducing the total oxygen available for combustion. If the leak is very small, there may be no change in rpms, but we may still see a slight change in the oxygen sensor reading. Use of a scan tool is a good idea to monitor the O2 sensor. The idea of using propane is scary enough. That is why it is only supposed to be used in short spurts. There is always the alternator located near by with its carbon brushes which might cause electric arcs. If propane is to work, there must be no wind to blow the propane away. I don't think it's a ECM (hardware) problem. Someone changed their ECM hardware and the problem did not go away. Most likely it's a leak or an oversight in the ECM software. I'll note your reference to "Champcaracing" in case I have new questions. Thanks.

montreal · Post by **montreal** » Mon Apr 18, 2005 12:51 am

Quote, originally posted by joatmon Â»If I figure out a solution, I will be sure to let you know, but it won't be before next winter that I will experience the problem again and will have an opportunity to troubleshoot.I was rather surprised to note that this morning my car pulsed. The overnight temperature had been about 35 degrees F. and when I started it at 9AM, the outside air temperature was about 55 degrees F. Rather than having the pulsing start 75 seconds after startup as in winter, it began about 20 seconds after startup. Rather than the pulsing lasting the typical 40 seconds as in the cold of winter, it lasted about 10 seconds.This says to me that not only has the ECU modified the idle fuel/air valve trim values for the coldest settings, but also for the not so cold positions in the table that matches actuator values to engine temperature and MAF inputs. The car is still too cold to use the O2 sensor, so these updated tables are all the ECU has to go on.Since the engine block is already warmer in spring than in winter, the motor spends less time prior to the start of the noisy phase, and the length of the noisy phase is shorter because it takes less time to raise the block temperture by a fixed amount in spring than in winter. We move up the table faster, so we are having each phase last shorter.This may be a sign that the air leak, if there is one, is getting larger over time. With some luck, it may get bad enough in any season to become identifiable.One thing for sure is that our engines should not be idling at over 2000 rpms during the first 2 minutes, summer or winter. Normal Vibe/Matrix engine's dont.

pmh013 · Post by **pmh013** » Mon Apr 18, 2005 9:53 am

That doesn't sound normal! Although, it does sound similar to mine back when I was having cataltyic converter problems. The exception though, is that mine did the engine-surge thing at highway speeds.I don't think I'd buy a car that sounded like that. There's a lot of used cars out there, and in all honesty, it's not like a Matrix is an extremely uncommon car. I bet in 10 years from now, you'll be able to find a used one easily. And if one (yours) sounds weird, you just phone the next listing in the newspaper. Period.

montreal · Post by **montreal** » Mon Apr 18, 2005 10:57 am

Quote, originally posted by pmh013 Â»That doesn't sound normal! I don't think I'd buy a car that sounded like that. There's a lot of used cars out there, and in all honesty, it's not like a Matrix is an extremely uncommon car. I bet in 10 years from now, you'll be able to find a used one easily. And if one (yours) sounds weird, you just phone the next listing in the newspaper. Period.This is the sort of answer that will encourage the arbitration board to order a repair.If the manufacturer were obliged to find the proper remedy, then there would eventually be a service bulletin or a software upgrade, and that would be in everybody's interest, because right now this problem appears to affect a few percent of owners and if the manufactures (Pontiac and Toyota) end up with a more robust car, then everybody wins. Thanks

ToolGuy · Post by **ToolGuy** » Tue Apr 19, 2005 9:26 pm

Quote, originally posted by montreal Â»The use of smoke dilutes the mixture but does not change the ratio as detected by the O2 sensor. The EGR valve has the same effect, it introduces gases that have already been burnt so there is neither oxygen nor unburnt hydrocarbons being added to the normal mixture. This extra inert gas that the EGR allows to enter the cylinder along with the fresh mix of gas and oxygen will have the effect of lowering the peak combustion temperature and reduce the NO2. But will this extra dilution actually cause the rpms to drop (stumble)? I'm not sure. Without hearing the motor suddenly change cadence when your smoke machine passes over an air leak, it would be hard to know which hose connection is faulty. On the other hand, the use of propane allows the oxygen entering via the air leak to be suddenly replaced with propane. That causes an immediate change in the (monitored) oxygen sensor voltage and perhaps a sudden drop in the idle rpms because we are reducing the total oxygen available for combustion. If the leak is very small, there may be no change in rpms, but we may still see a slight change in the oxygen sensor reading. Use of a scan tool is a good idea to monitor the O2 sensor. The idea of using propane is scary enough. That is why it is only supposed to be used in short spurts. There is always the alternator located near by with its carbon brushes which might cause electric arcs. If propane is to work, there must be no wind to blow the propane away. I don't think it's a ECM (hardware) problem. Someone changed their ECM hardware and the problem did not go away. Most likely it's a leak or an oversight in the ECM software. Our EVAP Smoke Machine is mainly used with the engine off and loads up what ever system you are testing with smoke, thus the leak will surface. The smoke has a UV Dye as well and then found with a black light. However I know techs use it for intake issues too, probably make their own adapter for that. The machine is widely used and can find a leak down to .010" or .25mm. It can be hooked up to the EVAP port or hoses on the EVAP canister. It has gas tank/cap adapters, exhaust and interior diffusers. Unfortunately I have only had limited us with our Smoke Machine. Maybe that is good though, never had a large reason to use it! The machine uses basically Vegetable oil, a diesel glow plug to heat the oil and shop air regulated to a very low PSI. Not sure though if it would work in the same manner as propane or have the same logic as the propane use. However if it does, it is much safer for you and the engine.Sounds like you can then rule out the ECM then...

montreal · Post by **montreal** » Tue Apr 19, 2005 10:20 pm

Quote, originally posted by MiVibe-ToolGuy Â»Our EVAP Smoke Machine is mainly used with the engine off and loads up what ever system you are testing with smoke, thus the leak will surface. The smoke has a UV Dye as well and then found with a black light. However I know techs use it for intake issues too, probably make their own adapter for that. The machine is widely used and can find a leak down to .010" or .25mm. It can be hooked up to the EVAP port or hoses on the EVAP canister. It has gas tank/cap adapters, exhaust and interior diffusers. ...This sounds like a great and safer way to go compared to using propane. I imagine that if one can place a TEE at the EVAP port and introduce the smoke under pressure, then it will try to escape through all the known and unknown paths.I imagine it is impossible to have both an intake valve and an exhaust valve open (fully or partially) on any cylinder at the same time, so it should be impossible for the smoke to escape through the exhaust system. That means that the smoke is going to head for the intake air filter via the slight opening in the throttle plate and the port in the idle air bypass valve. If we seal over the air filter (wrap the filter in Saran wrap and reinsert it), then that leaves the unforeseen cracks in the hoses and purge valves and cannister and brake booster as a possible escape route for the smoke.I'll definitely try to locate a garage offering this tool.Thanks for a great suggestion.

ToolGuy · Post by **ToolGuy** » Tue Apr 19, 2005 10:58 pm

If you feel up to it hopefully it does not come down to you fixing the car yourself, I have a portible Smoke Machine we used to make the larger DaimlerChrysler machine. I can certainly loan it to you if you think it will help. I just tested it and it is full of smoke. The shippng back to me may be expensive though, the unit is about two feet tall and one foot wide. Weighs about 15-20 lbs. You will need an air supply and it runs off 12 Volts.