Thread: Major work done....now having major problem

I took my 2002 grandprix gt into a local repair shop to have it looked over. To my surprise, they found alot more wrong than I imagined. They have replaced the intake manifiold gaskets, plugs, plug wires, both axles, an upper control arm bushing, both radiator hoses, both upper motor mounts, serpentine belt, and all four tires. after picking my car up (it was after the shop had closed) I test drove it on the highway. NOW the problem is that when I get it over 50 MPH and let off the gas pedal, the tachometer and speedometer fluctuate wildly followed by the transmission downshifting out of overdrive. I took it back the next morning. Well, after they had it another whole day ( a total of three days now including the original repairs) they can't seem to find the problem. I am hoping to gain any insight on a cause/fix so I can pass it along to them and get my beloved car back!! BTW, the tach/speedometer problem showed up only AFTER thier repairs.

mabye they messed up something with the ckp(crankshaft position sensor)? the unit itself/wires/unpugged? just a guess. how well do you trust this shop???? cause motor mounts dont need to be changed just like that, unless they are broken or cracking. how many miles, what year? and again, how well do ya know the shop? lol, i just never trust shops... heard too many bad storys lol.

I would rate the shop as good work but parts happy. It's a 2002 Grandprix GT sedan with 135,000 miles on it ( I bought it with 87K) I hear what you mean with the moto mounts, but since I am planning on increasing the performance of this car, I figured it couldn't hurt.

a parts happy shop is a bad shop...end of story. shops that say "well, this part should be replaced cause its gettin old and we dont want it too break on ya" are usually ripping you off. and if your goin performance, u would want to go with shorter poly mounts anyways... just take the car too the shop and have them fix it. if they charge you for anything in the process, then refuse to pay them.

Finally got it fixed...turns out the wiring that runs to the PCM under my CAI was rubbing against the bottom plate of my CAI. Looks like it wore through the insulation and started shorting out. New PCM and wiring fixed all. Thanx for all of your input!! Next is the suspension upgrade and the exhaust upgrade. Can't wait!!