04 GTP CompG Driving Rough

[CaptainPontiac]

I have a 2004 Grand Prix GTP CompG with a little over 1000 miles on it. Since purchase this car has developed a noticeable rough feeling coming from the driver’s side front end on acceleration or when cruising at speeds above 20 MPH. It is especially noticeable while the engine is running at 1200-1400 RPM. The car idles smoothly at 700 RPM but idling at 1200-1400 RPM is very rough and does cause vibration in the engine compartment and front seat area.

This rough feeling is not a tire balancing issue and it does not transmit through the steering column as a shimmy. It has a similar feeling to a problem with a wheel bearing on a previous car but this does not make any sound such as grinding, whining, etc.

I took the car back to the dealership and after they checked it out they dismissed the problem as road feel due to the performance tires and handling. I test drove an identical GTP CompG and it did not feel rough like this at all.

I would appreciate any suggestions as to what might be wrong with my car.

[Z987784]

I don't know what the problem could be. My only suggestion would be to keep taking the car back to get fixed. After a certain number of unsuccessful tries, you can probably take advantage of the lemon law and get a new car. (just a suggestion)

[jeffs_GTP_sleeper]

I am not a mechanic but I have read about people who had problems like this and they found out it was a pully that was wobbling slightly.

I think it was the idler pulley.

good luck!

[carnutcass]

Take the car to a different dealership.