2011 HHR:

When car goes into warmup phase, vibrations start building up through the steering column - reaches a max about 30 seconds - then drops down to zero. This has been happening ever since I had the car. Dealer says vibrations won't hurt anything - operating normal.

 

Its not normal, dealer needs to track down what is causing the vibrations, instead of saying, don't worry about it, it won't hurt anything! Just a wild guess, but perhaps its running too rich during warmup. Do you see any black smoke at the tailpipe when its doing the vibration dance?

 

im on my second HHR (lt & SS). both have had rough cold starts seems pretty normal for ecotecs. my brothers cobalt does it too

 

X 2, mine warms up smooth also..

 

also forgot to mention that i live in a generally colder climate....the rough starts were ~45 degrees or less which is nearly half the year. lol. in southern states it may not be as noticable but i wouldnt know. if its under warranty it could be worth it to have it looked at. i could be totally wrong assuming its just a cold start thing.

 

X 3...Not normal, not normal at all, mine warm up smooth as glass. Take the vehicle to another dealer in your area, you are being fed a line of BS by the first one.

 

I have two ecotecs. 1 has 132k and does not have any warm up issues when under 40*. Of course my temps never get below 25* at night hear in AZ. And we only have lows like that for 1 month.

 

I've had mine in temps that were in the low teens. Startups were quick and smooth. Rough starts are from my observations, not normal for the ecotec. You need to get a little more insistant with the dealer, or find another dealer that is willing to spend the time to troubleshoot the problem.

 

Mine is not excessive vibration or rough idle, or effected much by temperature. mine is a very short, quick vibration that sounds like it originates from side of driver side engine and transfers thru the steering wheel. It is only 1-2 seconds.

I remember reading what I think was a tsb, because the condition was described exact. I believe it was also noted that the buzz was heard in the cabin. It also listed a resolution and thats what I'm looking for.

 

Well it could be the alt drive belt tensioner per a TSB from way back when.
It could also be a dirty filthy TB blade. Be very careful when cleaning the throttle body