Quick question for those more knowledgeable than me...

When I first start up my car in the morning, regardless of temperature, my 2007 HHR engine has a very tight shake...after a short drive it seems to be ok but everyone once in a while at a red light I can feel the engine rattle. If I let go of the brakes and move the car just an inch the rattle will go away..

could it be brake booster check valve?

 

Which engine do you have ?
Is it auto or standard?
It could be an engine mount gone soft or other issues
Is there a CEL light?

 

I agree Engine mount.. If it is look into TTR motor mount. Great motor mount.
Or if it is the mount and you want to stay with Oem, I have one with 40,000 miles on it. I saved it after I put on the TTR motor mount. Make me an offer and it's yours!
Tim

 

its the 2.2L automatic transmission....
The engine shake/rattle is intermittent...Thats why I was thinking vaccum leak or maybe EGR valve..but no check engine lights...or dirty/loose spark plugs?

 

You have no EGR valve. Most vac leaks will throw a code, usually not seeming to be a vac leak.

 

$20+shipping?