GenVibe - Community for Pontiac Vibe Enthusiasts

I have a base 2007 Vibe and it idles perfectly steady at 700 RPMs. However, there's a little bit of vibration, but I'm not sure if it's a problem or just normal with these engines.

Basically, it's a calm vibration that isn't too crazy or anything. Mostly just feels like a massager if you had it on a very low setting, and it's prominent in the steering wheel and by my feet. When I turn on the AC (thus, upping the idle to around 850 RPMs), most of the vibration goes away. I'm just curious if this is a normal vibration or something that needs looked at. My honkin' 4.8L Silverado from the same year definitely doesn't vibrate this much at idle.

I recently cleaned the MAF sensor and throttle body, but I haven't noticed a huge difference in regard to the vibration.

On one level, this is subjective- some are okay with what you are describing.

The real question is, "what are the causes of 'excess' vibration at idle?"

A few things could be involved- others will add to the list...

[*]Vacuum leak - typically at intake manifold gasket, but any rubber hose or gasket on the intake side of engine is possible
[*]Idle Air Control Valve (IACV) could be dirty and/or have a bad gasket
[*]Mass Airflow Sensor (MAF) could be dirty [which you already cleaned]
[*]Air filter could be dirty/clogged

Chiming in here:

All in-line 4 cylinders are prone to vibration. Engineering deals with it in a variety of ways.
Engine mount bushings: Soft ones will reduce vibration at idle but will allow the engine to tilt at take off and sudden power demand etc. Hard ones will cause vibration at idle but handle the torque inputs better. Our Vibes have hard ones. My wife's '10 Ford Focus has fairly soft ones and and one of them is liquid filled and wears out relatively quickly.
"Smart" engine mounts: they have a magnetically reactive liquid in them that can instantly make the mount hard to deal with torque and go soft when idling. Some Acura's have them.
Balance shafts are used in larger I-4 engines and probably the best way of handling the inherent vibration.

H-4 engines (air cooled Beetles and Subaru) have less vibrations than I-4 but are more expensive to manufacture.
6 cylinder and 8 cylinder in just about any configuration are much better balanced. If you want it silky smooth get a V12......

If your engine is in proper tune the odds are it's vibrating normally. Something to get used to.
I would include the spark plugs into things to check.

Bad or weak motor mounts will let the engine vibrate more then when it was new. You may want to check your motor mounts.

I also have vibration at idle and it's starting to get annoying, so thread is very timely. Unfortunately, I have more questions for you guys and no answers:

How can you detect/diagnose the vacuum leak mentioned above?
Where is the IACV and same question, how can you diagnose it?

Is there any way to diagnose the condition of the motor mounts without removing them?
I am basically aware of three mounts, but some places I see references to a transmission mount. Where is this, and is this different from one of the three motor mounts?

Vibrologist mentions a balance shaft in I-4 engines. Does 1zzfe have that? I'm guessing not.

Lastly, could it be the harmonic balancer? Or would that cause vibrations also at higher RPM, i.e. not just at idle?

Thanks!

Finding vacuum leaks use carb or throttle body clean. Spray area and if engine RPM's change, you have a vacuum leak at that location. Be sure to spray around the intake manifold and all hoses. This includes the power brake vacuum line and the vacuum lines running back to the gas tank under the car.

IACV is part of the throttle body. In the upper right hand corner of this page is a box that says "Search", use it. You will find posts about cleaning the IACV, and if I remember right, there are pictures too. This has more to do with idle speed then anything else.

Motor mounts, as vibrologist said, look for cracks in the rubber. Compare pictures of new mounts to the ones you have. Pictures can be found at http://www.rockauto.com of most any part. The rubber portion of the mounts that are round in shape on the out side, when new, will have the inside hole centered in the rubber. If the inside hole is not centered in the rubber, it has deformed over time. Watch for motor movement when under load as vibrologist suggested. There will always be some movement as that is what the mounts are for but there should not be a lot. You can watch the mounts and see how much they compress under load. If the rubber compresses a lot replace the mount. Also use the "Search" on this board about motor mounts because I have seen posts here in the past about this topic.

This motor does not have balance shafts, which really do not balance anything. Balance shafts are a counter balance of the forces from the pistons and crankshaft movement used on line motors or single cylinder engines. They can help smooth out an engine in some RPM ranges but also add more moving parts that can wear out and take more power from the engine to turn the shaft or shafts.

No harmonic balancer either. Harmonic balancers are typically used to dampen torsional vibrations with in the crankshaft. In most 4 cylinder engines there is not enough crankshaft length or journals where harmonics become a problem for the crankshaft, so a balancer for it is not needed.

Thanks for the info. Will try the carb cleaner test. Regarding the mounts (there have been quite a few of these threads of late) it seems that the terms motor/engine/transmission mounts are used interchangeably. (But based on the parts websites and the diagrams, it seems there are four altogether, front, back, left, right). A few threads mentioned that a worn right hand one contributes a lot to the vibration... Are the aftermarket ones really to be avoided? Someone mentioned the compounds are not as good as the original.

There are four mounts:
https://www.rockauto.com/en/moreinfo.ph ... 59&jsn=340

RockAuto sells a kit (linked above) that contains three motor mounts and one transmission mount.

The favorite brands on their site are Anchor and DEA/MRC.

Check your wiring for your IGN system as well
https://share.qclt.com/%E4%B8%B0%E7%94% ... 020000.pdf
something was chew chew chewing my sparking coil wire

I'm still checking on some of the possibilities of idle vibration on the 03 base Vibe (I know, it's been a year, I'm in no rush) -- didn't find vacuum leak with the spray method, cleaned the TB as much as possible without taking it off (maybe I'll take it off if/when I change coolant, and do intake gasket and new thermostat as well), replaced passenger side motor mount (when putting in a new acc belt tensioner).

But I had a another idea... Has anyone done or knows how to properly do a cylinder power balance test on the 1ZZFE?

I know some options are to remove the coil pack connectors one at a time, to remove the injector connectors one at a time, and watch the RPM.

But can the '03 Vibe ECU do this test with an appropriate scan tool or the Toyota techstream software, or is it too old a design?

Does the ECU compensate if done manually (i've seen this mentioned elsewhere)?

Thanks

"But can the '03 Vibe ECU do this test with an appropriate scan tool or the Toyota techstream software, or is it too old a design?"

Not that I know of. This type of test could or can cause damage to other systems in the car like the catalytic convertor.

"Does the ECU compensate if done manually (i've seen this mentioned elsewhere)? '

Yes.

If you are thinking about this test then you may want to do a compression test on each cylinder or pull the injectors and take them to be tested for volume and spray pattern.

jolt wrote: ↑Mon May 06, 2019 11:29 am Not that I know of. This type of test could or can cause damage to other systems in the car like the catalytic convertor.

Power balance test seems to be fairly standard, it's in at least two technician training books I've looked at and likely a shop would do it if I took it in. Having said that, yes, depending on how it's done, it could put raw fuel in the catalytic converter, but it's not advised to do it for long on any cylinder. Other than that, not sure what would be damaged. I'm a little surprised that nobody has done this on this genvibe (I did search for it, will keep searching)...

jolt wrote: ↑Mon May 06, 2019 11:29 am If you are thinking about this test then you may want to do a compression test on each cylinder or pull the injectors and take them to be tested for volume and spray pattern.

Yes the wet/dry compression and leakdown tests are also something I've been thinking of, but that would require an air compressor (anyone know what spec in cfm?) but anyway it would be good to know if any cylinder is not pulling its weight.

ehoff121 wrote: ↑Thu May 03, 2018 12:01 pm There are four mounts:
https://www.rockauto.com/en/moreinfo.ph ... 59&jsn=340

RockAuto sells a kit (linked above) that contains three motor mounts and one transmission mount.

The favorite brands on their site are Anchor and DEA/MRC.

I think Energy Suspension makes a urethane motor mount bushing for the Vibe/Matrix too.