I have a problem with my 2006 Cobalt SS non-supercharged. After I got some service done at the dealer I noticed my engine started bogging and ticking and clunking. It also has blow back when you take the oil cap off and some oil sprays out. I tried getting the dealer to look at it, but they said it was normal because it doesn't have a PCV valve.

Can someone help me narrow down what the problem is?

 

blow-by. possibly piston rings

 

The oil filter could be bad ,did you have it changed at the dealer as in the work you had done.

#07-06-01-016 Information on Internal Engine Noise or Damage After Oil Filter Replacement - (Aug 14, 2007)


What kind of work did you have done.

 

I had the rear bumper replaced. Totally unrelated to the problem, but they source it out to another bodyshop so they had to drive it there. When I got it back the problem occured. I still have warranty left, probably around 20k left.