Car vibration since outside temp below 32F

[DaveLS]

Hey guys,

I drive a 04 v6 and recently, outside temp as been constantly below 32F and I've been noticing a clear vibration in my steering wheel and in my brake pedal when I am stopped at a light/stop (idling). It does it everytime (not only when the vehicule is cold). When I'm driving though I don't feel the vibration. The rpm gage is fine (doesnt fluctuate when i'm idling). I always felt a very slight vibration but never like what I am experiencing now. Also, no codes are popping up other than the cats working below threshold ones.

There are a couple of things I identified that may be the culprit. For the first time in a looong time I filled my car with Costco 91 instead of Shell 91, I deleted the content of my cats a couple of months ago (empty cats are still on) and I figured that it may be the gas the create the vibration or the empty cats usual vibration mixed with the cold temp as been causing my car vibrations.

What do you guys think could be the culprit of my problem ?? Thanks !

 

[joegr]

1) The first suspect with the LS should always be coils (and plugs).
2) Any air intake leaks.
3) Intake runner valves.
4) Dirty fuel injectors.
5) ?

 

[DaveLS]

1) The first suspect with the LS should always be coils (and plugs).
2) Any air intake leaks.
3) Intake runner valves.
4) Dirty fuel injectors.
5) ?

Ok I will look into that for sure. The one question that I have though is that if the culprit was to be one of the things you pointed out shouldn't the vibration be constant regardless of the temperature? For example, today was a little warmer (around 50F) and I only felt very slight vibrations.

 

[joegr]

Well, any marginal problem can be made worse by a change in temperature. Intake leaks do seem to get worse at lower temperatures. Of course it could be something else. If you are thinking it might be a temperature sensor, then plug in a scan tool at look at all the temperature readings to see if any seem to be crazy.

 

[trk pny]

Does the car vibrate when in park and in gear? I know you said its when idling. If it is only when in gear, you might check the rubber mount at the tranny tail shaft end piece. Ours was broke and when in gear it would have a vibration you could feel in the car but of you shifted it to "park", the vibration was not there.