Rough idle

[BurgerMcDo]

Hi,

I am a bit concern about the mild vibrations during idle. I have just replace the spark plugs, have the throtle body cleaned and replace the air filter and yet i can still feel the vibrations. Any Idea whats the problem? Thank you.

 

[millerbl00]

Depending on age I would check/replace motor mounts.

 

[BurgerMcDo]

my car has 64k miles. Thank you for the advice.

 

[gathermewool]

Did you gap the new plugs to spec?

 

[eljefino]

Try revving above idle by only about 50 rpm. If it gets smoother it's the motor mounts as mentioned above. (resonant frequency shaking the chassis).

If it's still bothersome you have an engine performance issue.

 

[BurgerMcDo]

the sparks plugs are OEM

ok im gonna try your instructions later. thank you. gonna reply later.

 

[dwendt44]

Try running a strong injector cleaner for a bit.
SeaFoam is great.

 

[mechtech2]

Unbalanced injectors due to deposits, or combustion chamber deposits, can certainly contribute to rough running, especially at idle.
But Seafoam is simply a solvent - it is a dated technology. Better than nothing, I suppose.
Use an amine type of strong cleaner in a tank of gas. Chevron Techron, Amsoil PI injector cleaner, or Redline SI-1.
Vacuum leaks in any lines, their connections, and the intake system are another thing to check. Esp the PCV system.
Also, get a can pf spray MAF cleaner and clean the MAF sensor.

 

[sunfire]

Cleaning the TB with CRC TB cleaner and intake helped a bit with my 05 Corolla's rough idle. Since my second tank of MMO in the gas I hardly ever notice rough idle anymore.

 

[BurgerMcDo]

Yeah, I am currently running my car with seafoam. I notice improve mpg but i can still feel the rough idle. my tank is almost empty. This time im gonna fill it up with chev techron fuel system cleaner. Hmmm I acutaly filled up my tank half full then put in 1 bottle of seafoam making it more potent. guess i'll be doing that too with chevron.

 

[Nick R]

I don't know much about that VW 2.0, but maybe it's just the nature of the beast, as it is with my cavalier. The 2.2 isn't ROUGH by any means, but it has a little bit of vibration at idle, especially in the steering wheel.

 

[BurgerMcDo]

Hmm.I don't know. I have always thought that cars should have a smooth idle. I' am kinda looking at the engine mounting problem. I hope thats it.

 

[mechtech2]

If it was smooth before, but rough now, it indicates a change, and a problem.
Most 4 cylinder engines have some idle vibration. They seem to like 1025-1050 RPMS to idle smoothly. I've noted this on all sorts of cars and motorcycles. But this is too high for modern computer controlled cars.