If someone has any advice on a hesiation issue in a 2000 Grand Prix GT that seems to happen more when the car is accelerating slowly on the highway and the tach is usually reading between 2000-2500rpm when this happens and it starts bouncing up and down rapidly within that 500 rpm range, but if I accelerate harder and the car downshifts it is fine. I have changed out the fuel filter, oxygen sensor, new plugs and plug wires, new coil packs, cleand the throttle body, the trans is new and I took it back and had them diagnose the trans and everything checked out fine with that…Im out of ideas and the service engine soon light is not on, so no one can diagnose it from that aspect. It has been recommended that I change out the modulater that sits uner the coil packs. The engine is not making any knocking or pinging noises either. I am not loosing any coolant, I have been told that it is possible that I have coolant leaking into the oil as well…I am up for any suggestions at this point
First get that possibility of leakage of coolant into the oil checked out. There’s no sense doing anything else until you know for sure the answer to that question.