Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
Hello, my name is***** for the question. Can you tell me if the check engine light is coming on? Also does the car use coolant at all?
Thanks Mike. There are some possibilities here. Start by checking the inside of the throttle body. Since it is clean you should be able to open it and see if there is a ridge worn in it where the plate sits. If there is then replace the unit. If that is fine then you may have an EGR that is sticking open or most likely you have a failing intake manifold gasket. This is the most common on this engine. Has this been checked?
The IAC is controlled solely by the computer. The computer is going to adjust the idle.If there is an intake leak then the computer may try and adjust the idle with no luck due to the leak in which time it will give up.
It really sounds like an intake gasket leak. This should either be smoke tested or you can try using throttle cleaner to see if you can detect a leak. With the engine idling, spray the cleaner around the intake and listen for an rpm change. If there is then there is a leak.