Rough Idle ( LONG )

Discuss any problems, warranty, repair, or replacement issues you are having with your Vibe & Matrix
Post Reply
User avatar
cptnsolo77
Posts: 1593
Joined: Sun Jul 29, 2007 4:05 am

Rough Idle ( LONG )

Post by cptnsolo77 » Sun Apr 18, 2021 7:55 pm

I have been tracing a vibration in idle for longer than I even care to admit. During warm up ( until operating temp ) it idles rough. After it warms up, it get better but still not where I know it should be. I know the 1ZZ isnt the smoothest by design but Heres my story.

-Replaced all engine/trans mounts twice and I will explain why: Early 2020 I replaced the front and side mounts myself. The rear mount ( firewall side ) looked to be too much to handle so I decided to have a mechanic take care of that one. COVID came in and I did not feel comfortale taking it to a shop...so for 9 months the car vibrated terribly and violenty. I found a mechanic that would come to my house so it will be safe repair pandemic wise. He replaced the rear mount and it was shot, completely torn. Practically driving with 3 mounts. After having that last mount replaced, I still had this vibration at idle. Being that I drove with a mix of new/old mounts....I suspected after 10,000 miles maybe I prematurely worn the new ones. So I did a little experiment: I replaced one mount at a time and see if the issue improved...and it did. As I replaced each mount, the vibration became less and less. So its looking good here right ? When I had the rear mount left and still just a bit of vibration, I thought that this last mount would finally do the trick. It did not change anything. So I guess I can rule out engine/trans mounts now LOL. The mounts are all Toyota OEM.

-I do have a PO 442. Replaced both gas caps, purge and vent evap solenoids had a mechanic do a smoke test. He couldnt find any leaks, he suspects the charcoal canister maybe leaking internally. In my opinion if the leak is that small, it wouldnt contribute to THAT rough an idle. I could be wrong though.

-Replaced all plugs in the last month, the coils are Denso units that are 2 years old from a missfire I had, so replaced all 4.

-Fan assembly. The other day I noticed when I had the key on/ignition off there was a vibration in the steering wheel. Weird because the engine isnt running. The fan was on high ( car was just driven and I was ready to start it again ) I did this a 2 more times and noticed the same issue. The fan seem to have excessive vibration on high speed. When the car was off I turned the fan blade by hand and just before it stopped i heard a small squeal. My logic...the bearings are worn, and putting a electrical load and causing a little vibration. New fan assembly and no change. I also noticed the vibration was more apparent when the AC condenser fan kicked in on high and that also led me to beleive the fan assembly may be causing my issue. That leads me to the next thing....IAC valve. Im also experiencing a hard start when the car has been sitting after it has been driven. It starts up fine in the morning.

-The IAC and throttle body was cleaned 3 years ago. Aprox. 25K miles ago. This was the 2nd time it has been cleaned. I cant see it being that dirty that it would cause rough idle. Even at the dirtiest it never idled this way. Unless the IAC is just faulty. I do have 272,000 miles now. With the AC on it does idle about 800 RPMS and the idle doesnt dip with a load from the AC. So its seems the IAC is working correctly. I understand that the IAC is supposed to bump up the RPMs when the AC condenser fan kicks in, but my RPMs are steady at 800 and not fluctuating. Again....I can be wrong, thats why I havent fixed it LOL.

Any ideas ? Im stumped. Im starting to think I did some kind of damage driving with a bad motor mount for so long.
* 2003 Vibe Auto Satellite Silver w / Moons & Tunes
* Kenwood Excelon KDC-X597
* Polk DB651-Speakers
* Soundproofcow Roadblock R sound deadening in all doors
* Drop In K & N Filter
* NGK Iridium IX Plugs
* 27 MPG City/Highway with AC on

User avatar
joatmon
Posts: 9570
Joined: Fri Mar 21, 2003 5:19 am
Location: SMC MD

Re: Rough Idle ( LONG )

Post by joatmon » Wed May 26, 2021 5:32 am

I can't be of much help. The matrix manual offers these possible causes for a rough idle
1. ISC valve circuit
2. Injector
3. Ignition coil (w/ Igniter) circuit
4. Compression
5. Fuel pump control circuit
6. Back up power source circuit
My second vibe constantly threw P044X codes, related to evap control, I assumed a vacuum leak somewhere, but never noticed a resulting rough idle. Never solved it, just kept the scangauge connected to reset the CEL when it came up

User avatar
cptnsolo77
Posts: 1593
Joined: Sun Jul 29, 2007 4:05 am

Re: Rough Idle ( LONG )

Post by cptnsolo77 » Fri May 28, 2021 12:56 pm

Thx for the help anyway. My next step was going to clean the throttle body and MAF ( even thought I doubt thats the issue but you never know ) from there its the IAC. After that I dont know, I will probably swap out each coil with a good spare I have and see how it drives. I just threw in some BG fuel cleaner ( scotty kilmer recomended ) It seems a little better under throttle. I have the torque app and im going to check what the RPMs are before and after the AC is on....maybe its not raising the idle high enough. Whatever it is, it cant be that complicated a fix. We shall see..... :lol:
* 2003 Vibe Auto Satellite Silver w / Moons & Tunes
* Kenwood Excelon KDC-X597
* Polk DB651-Speakers
* Soundproofcow Roadblock R sound deadening in all doors
* Drop In K & N Filter
* NGK Iridium IX Plugs
* 27 MPG City/Highway with AC on

jolt
Posts: 877
Joined: Sun Mar 02, 2014 2:07 am
Location: Twin Cities, Minnesota

Re: Rough Idle ( LONG )

Post by jolt » Sun May 30, 2021 9:34 pm

I would check the compression on each cylinder. If you have a mechanical issue none of these other things are going to fix it.

Of coarse a small vacuum leak at a intake manifold runner could cause an idle issue. You could try to pinch off one vacuum hose at a time to see if it effects the idle. Or just change out the intake gasket to cross that off the list as I would think that the gasket was changed out sometime in the past but you never know.

With that many miles on it, it could be a bad fuel injector. The injectors do wear out and the spray pattern goes bad. The cars ECU can check the injectors electrical but not the mechanical spray pattern. Since most gasoline injectors are not rebuild-able, most injector shops do not test them. You could buy one injector and swap it one at a time with the old injectors and see if the idle improves.

Pull the valve cover and check the valve clearances, look the valve train over for any wear. Turn the engine over and watch to make sure all the valves are moving their full range of travel. A bad camshaft lobe, rocker arm, valve spring could cause idle issues and would be very odd but with that many miles, you just never know. These things can also effect the compression so this could be looping back to my first item here.

User avatar
cptnsolo77
Posts: 1593
Joined: Sun Jul 29, 2007 4:05 am

Re: Rough Idle ( LONG )

Post by cptnsolo77 » Tue Jun 01, 2021 2:51 pm

I had a mechanic do a smoke test and he couldnt find anything. I have 21 inches of engine vac ( via the torque app ) so the engine seems pretty healthy from that point of view. I didnt do a compression test and you may be on to something. The intake manifold gasket was changed back in 2013 :lol: :lol: and was replaced with the orange one...but you never know. Maybe I will check the manifold bolts, maybe they came a little loose from all this vibration ? I was thinking a bad injector as well. I threw in some BG fuel cleaner and it seemed to help a little. This is one is definitely frustrating. The only other issue that the Vibe has given me a hard time with was low idle that eneded up being a dirty IAC. Tracing that issue was a walk in the park compared to this one. I know im at 274,000 but I know she has a lot left in her.....and I dont want a car payment :roll: Thanks for the advice though, any help is appreciated ! 8-)
* 2003 Vibe Auto Satellite Silver w / Moons & Tunes
* Kenwood Excelon KDC-X597
* Polk DB651-Speakers
* Soundproofcow Roadblock R sound deadening in all doors
* Drop In K & N Filter
* NGK Iridium IX Plugs
* 27 MPG City/Highway with AC on

jolt
Posts: 877
Joined: Sun Mar 02, 2014 2:07 am
Location: Twin Cities, Minnesota

Re: Rough Idle ( LONG )

Post by jolt » Thu Jun 10, 2021 6:58 pm

Hi cptnsolo77,

Did you try pinching off different vacuum lines to see if that effected the idle? If a vacuum line is hooked to a intake manifold runner, and not to the plenum, a vacuum leak can cause that runners cylinder to run lean and miss. This can cause a rough idle condition.

Has the PCV valve been changed?

dale321
Posts: 9
Joined: Tue May 04, 2021 8:06 pm

Re: Rough Idle ( LONG )

Post by dale321 » Thu Jun 10, 2021 8:32 pm

cptnsolo77 wrote:
Fri May 28, 2021 12:56 pm
Thx for the help anyway. My next step was going to clean the throttle body and MAF ( even thought I doubt thats the issue but you never know ) from there its the IAC. After that I dont know, I will probably swap out each coil with a good spare I have and see how it drives. I just threw in some BG fuel cleaner ( scotty kilmer recomended ) It seems a little better under throttle. I have the torque app and im going to check what the RPMs are before and after the AC is on....maybe its not raising the idle high enough. Whatever it is, it cant be that complicated a fix. We shall see..... :lol:
I run the torque pro all the time - BG ? - i watch alot of scotty too , he has good advice from his experience -
on my08, rpms at idle (after warmup ) run between 600 and 700 .. with a/c on this bumps to 700-800 approximately . One thing torque doenst pickup is the tranny temp .. i would really like to monitor that .. i see just about every other thing including for and aft CAT temp /O2 sensors .. but no tranny temp .. even on mine with less than 40k miles .. idle without a/c has more vibration than with the a/c on .. the hotter the water temp is the slower the idle (until electrical load like radiator fans kick on) and the more the vibration ..

zbyers
Posts: 1628
Joined: Thu Apr 03, 2014 6:12 pm
Location: Sheffield, Pennsylvania

Re: Rough Idle ( LONG )

Post by zbyers » Fri Jun 11, 2021 4:58 am

dale321 wrote:
Thu Jun 10, 2021 8:32 pm
One thing torque doenst pickup is the tranny temp .. i would really like to monitor that .. i see just about every other thing including for and aft CAT temp /O2 sensors .. but no tranny temp .. even on mine with less than 40k miles .. idle without a/c has more vibration than with the a/c on .. the hotter the water temp is the slower the idle (until electrical load like radiator fans kick on) and the more the vibration ..
There is no temp sensor on the transmission to measure it.

It is normal for idle to be slightly higher with AC/heat on.

It is normal for idle to drop as the engine warms up.
'74 Thing, '79 El Camino, '83 VW Vanagon DoKa '91 Vanagon,
'04 & '06 CRV, (2) '03 Base, '04 GT, '06 AWD, '07 Base, '17 Frontier CCLB

Byerscrew Garage, GenVibe Facebook, How-To Index
Everything You Need To Know About the Pontiac Vibe

User avatar
cptnsolo77
Posts: 1593
Joined: Sun Jul 29, 2007 4:05 am

Re: Rough Idle ( LONG )

Post by cptnsolo77 » Fri Jun 11, 2021 6:31 pm

jolt wrote:
Thu Jun 10, 2021 6:58 pm
Hi cptnsolo77,

Did you try pinching off different vacuum lines to see if that effected the idle? If a vacuum line is hooked to a intake manifold runner, and not to the plenum, a vacuum leak can cause that runners cylinder to run lean and miss. This can cause a rough idle condition.

Has the PCV valve been changed?
I can check but I havent done any work on the car that required disconnecting vaccum lines. Yes the PVC was changed in 2018. I routinely change my oil so I cant see it sticking, but you never know.
* 2003 Vibe Auto Satellite Silver w / Moons & Tunes
* Kenwood Excelon KDC-X597
* Polk DB651-Speakers
* Soundproofcow Roadblock R sound deadening in all doors
* Drop In K & N Filter
* NGK Iridium IX Plugs
* 27 MPG City/Highway with AC on

User avatar
cptnsolo77
Posts: 1593
Joined: Sun Jul 29, 2007 4:05 am

Re: Rough Idle ( LONG )

Post by cptnsolo77 » Fri Jun 11, 2021 6:44 pm

dale321 wrote:
Thu Jun 10, 2021 8:32 pm
cptnsolo77 wrote:
Fri May 28, 2021 12:56 pm
Thx for the help anyway. My next step was going to clean the throttle body and MAF ( even thought I doubt thats the issue but you never know ) from there its the IAC. After that I dont know, I will probably swap out each coil with a good spare I have and see how it drives. I just threw in some BG fuel cleaner ( scotty kilmer recomended ) It seems a little better under throttle. I have the torque app and im going to check what the RPMs are before and after the AC is on....maybe its not raising the idle high enough. Whatever it is, it cant be that complicated a fix. We shall see..... :lol:
I run the torque pro all the time - BG ? - i watch alot of scotty too , he has good advice from his experience -
on my08, rpms at idle (after warmup ) run between 600 and 700 .. with a/c on this bumps to 700-800 approximately . One thing torque doenst pickup is the tranny temp .. i would really like to monitor that .. i see just about every other thing including for and aft CAT temp /O2 sensors .. but no tranny temp .. even on mine with less than 40k miles .. idle without a/c has more vibration than with the a/c on .. the hotter the water temp is the slower the idle (until electrical load like radiator fans kick on) and the more the vibration ..
800 RPMs is what it idles at when the AC is on, so it seems like the IACV is functioning. Its WEIRD....lately has been idling smoother. The fuel cleaner didnt too much honestly and that was 3 weeks ago. About 2 weeks ago I was driving and it seemed to idle better, but i havent done anything. I dont think it would have been the fuel cleaner because I already went through the fuel cleaner and refilled the tank. The weather has definitely been very hot....making me think the issue is temperature related. BTW I replaced the engine temp control sensor too. I replaced it when when I was trying to diagnose a hard start when hot issue, that ended up being a bad coil :lol:

Me stumped :lol:
* 2003 Vibe Auto Satellite Silver w / Moons & Tunes
* Kenwood Excelon KDC-X597
* Polk DB651-Speakers
* Soundproofcow Roadblock R sound deadening in all doors
* Drop In K & N Filter
* NGK Iridium IX Plugs
* 27 MPG City/Highway with AC on

User avatar
cptnsolo77
Posts: 1593
Joined: Sun Jul 29, 2007 4:05 am

Re: Rough Idle ( LONG )

Post by cptnsolo77 » Fri Jun 11, 2021 6:46 pm

cptnsolo77 wrote:
Fri Jun 11, 2021 6:44 pm
dale321 wrote:
Thu Jun 10, 2021 8:32 pm
cptnsolo77 wrote:
Fri May 28, 2021 12:56 pm
Thx for the help anyway. My next step was going to clean the throttle body and MAF ( even thought I doubt thats the issue but you never know ) from there its the IAC. After that I dont know, I will probably swap out each coil with a good spare I have and see how it drives. I just threw in some BG fuel cleaner ( scotty kilmer recomended ) It seems a little better under throttle. I have the torque app and im going to check what the RPMs are before and after the AC is on....maybe its not raising the idle high enough. Whatever it is, it cant be that complicated a fix. We shall see..... :lol:
I run the torque pro all the time - BG ? - i watch alot of scotty too , he has good advice from his experience -
on my08, rpms at idle (after warmup ) run between 600 and 700 .. with a/c on this bumps to 700-800 approximately . One thing torque doenst pickup is the tranny temp .. i would really like to monitor that .. i see just about every other thing including for and aft CAT temp /O2 sensors .. but no tranny temp .. even on mine with less than 40k miles .. idle without a/c has more vibration than with the a/c on .. the hotter the water temp is the slower the idle (until electrical load like radiator fans kick on) and the more the vibration ..
800 RPMs is what it idles at when the AC is on, so it seems like the IACV is functioning. Its WEIRD....lately has been idling smoother. The fuel cleaner didnt too much honestly and that was 3 weeks ago. About 2 weeks ago I was driving and it seemed to idle better, but i havent done anything. I dont think it would have been the fuel cleaner because I already went through the fuel cleaner and refilled the tank. The weather has definitely been very hot....making me think the issue is temperature related. BTW I replaced the engine temp control sensor too. I replaced it when when I was trying to diagnose a hard start when hot issue, that ended up being a bad coil :lol:

Me stumped :lol:
* 2003 Vibe Auto Satellite Silver w / Moons & Tunes
* Kenwood Excelon KDC-X597
* Polk DB651-Speakers
* Soundproofcow Roadblock R sound deadening in all doors
* Drop In K & N Filter
* NGK Iridium IX Plugs
* 27 MPG City/Highway with AC on

dale321
Posts: 9
Joined: Tue May 04, 2021 8:06 pm

Re: Rough Idle ( LONG ), my vaccuum

Post by dale321 » Mon Jun 14, 2021 7:05 pm

BTW: i was watching the vaccuum closely and I'm getting about 23-24at idle , drops a little with the A/C on .. and on kind of a downshift a 27.9 psi was recorded. Engine is prob. in it's prime with less than 40k miles on it ..

jolt
Posts: 877
Joined: Sun Mar 02, 2014 2:07 am
Location: Twin Cities, Minnesota

Re: Rough Idle ( LONG )

Post by jolt » Tue Jun 15, 2021 9:00 pm

cptnsolo77 wrote:
Fri Jun 11, 2021 6:31 pm
jolt wrote:
Thu Jun 10, 2021 6:58 pm
Hi cptnsolo77,

Did you try pinching off different vacuum lines to see if that effected the idle? If a vacuum line is hooked to a intake manifold runner, and not to the plenum, a vacuum leak can cause that runners cylinder to run lean and miss. This can cause a rough idle condition.

Has the PCV valve been changed?
I can check but I havent done any work on the car that required disconnecting vaccum lines. Yes the PVC was changed in 2018. I routinely change my oil so I cant see it sticking, but you never know.
You do not remove the vacuum lines, just pinch them off one by one. These work well for most lines: https://www.amazon.com/Lisle-22850-Hose ... 572&sr=8-5

jolt
Posts: 877
Joined: Sun Mar 02, 2014 2:07 am
Location: Twin Cities, Minnesota

Re: Rough Idle ( LONG )

Post by jolt » Tue Jun 15, 2021 9:07 pm

Standard engine vacuum is measured in inches of mercury and not pounds per square inch (psi). It is a vacuum, not a pressure, which is relative to where you are in elevation.

Post Reply