08 gp runs and shifts odd

[69prixguy]

I have a 2008 gp with 58k, Its kinda hard explaining what my car is doing but ill tr my best.

It idles and sounds fine. When I drive it feels like the car is pulling a heavy load. If I take off fairly fast, the rps get to about 3k and the car takes off like its supercharged which it is not. when I go up a hill, I give it more gas and the rps go down, it doesn't shift till i am giving it atleast 1/2 throttle. It also feel like it surges or something not alot but its constant. It still feels like this no matter what gear i put it in but mostly feel this going up hills. The best i can describe this is when my 2 cycle 2 cylinder snowmobile is fouling a plug and it get a spark here and there to the fouled plug. Also in the past, a few times the car would feel like the exaust was blocked and very sluggish and the exaust was noticably louder. Ofcoarse the dealer found nothing! That would come and go not to often. Any ideas of what could be the issue? No engine service light has ever come on.
John

 

[cerick08GP]

Sounds like the ignition control module to me. If so you’ll eventually start getting random misfires.
If it was my car I start by looking at the wires, plugs and coils. All these can be tested easily, and are inexpensive. Who knows you might get lucky. Besides the ICM isn’t cheap, and to replace it you have to go through the coils anyway.
Good luck

 

[69prixguy]

thanks, would the dealer be able to test the module to see if its ok or not? Its still under warranty.

 

[starscream5000]

Why are you even posting on here right now if it's still under warranty? Take it in and let GM fix it.

 

[69prixguy]

Because they say there is nothing wrong with it. They say the same thing about it shaking when I give it gas.. "its the tires" 3 different pairs of tires are going to do the exact same thing?

 

[Couch]

try another dealer. if it's anything like here i can choose from half a dozen GM dealers to go to.

 

[FordMan77]

Since yours is an 08, I'd try removing and cleaning the throttle body, then clean the MAF and see what you get. If the TB is dirty then it may be messing w/ your DBW system.