Engine Performance problem
2005 Pontiac Grand Prix 6 cyl Front Wheel Drive Automatic 75000 miles
My 05 Pontiac GP from the day I bought it (2yrs ago with 32000 miles on it)I have had this intermittent problem (happens once or three times a month). Almost always with a cold engine (but happens when the ambient temp is above 70F) when the engine start you can notice a fluctuating tachometer (more than normal), under light acceleration there is a noticeable stumbling, under hard acceleration you can notice a loss of power. No trouble lights have come on or codes set in the computer. To make this go away all you have to do is pull over shut off the engine and wait 10 seconds and start the engine (no more fluctuating tachometer or loss of power). When this happens the instantaneous MPG on the trip computer shows 3/4 to 1/2 of what it does when the problem is not there. Once in a while I it will start and and then stall (this is unusual) but the next crank it will be fine. I have taken it in to the dealer and to my mechanic and neither can figure it out. The dealer said they re-calibrated the crank sensor but the next day it did it again.
have the same problem?
Tuesday, July 27th, 2010 AT 5:28 AM