I still have a serious clunk in the drive train of my GXP and I have had it to the dealer twice and they contend that they cannot duplicate the problem.

I have stated this once on here a while ago but I'll state it again because my warranty is
about to expire.

After accelerating, you let your foot off the gas pedal and start coasting. When you press the gas pedal again, either hard or soft, there is a big clunk in the drivetrain somewhere. It is less pronounced if you actually use the brake and slow down first.
It is more noticable on the highway if you are using your accelerator to monitor your speed. It doesn't do it when the car is cold.

The first visit I told the dealer the symptoms and suggested the transmission. The second visit I said it was worse and also check the motor mounts. The service manager said they couldn't get the car to clunk.

It'* really bad, I don't see how they couldn't duplicate it. Any ideas?

There is another Pontiac dealer on the highway about 15 miles from me.

Tell them to hop in and take a ride with you!

if they cant duplicate teh problem, they cant duplicate the problem, it happens all the time.. Be patient with them, and try to take a drive with the tech so you can actually show it for yourself

It'* almost like I have to tell them what'* wrong with it myself, (which is why I'm fishing for possibilities). I had to tell the Chevy dealer that my steering shake and clunk was the intermediate steering shaft before they would fix my Tahoe. They said it was tires, and alignment. Reading on Bonneville Club helped me narrow it down to the shaft problem (even on a Tahoe). Well if someone else had this same issue on a GXP I might be able to talk the service manager into a repair. They are not thrilled about searching and searching for warranty work, I imagine.

I may try to set up a drive with a tech. This dealer is really stuffy. They still make you set up an appointment days in advance. Most dealers just tell you to drop it off any morning, first come, first served.

possibly motor mounts on front, check by starting car and pressing brke and then while depressed put car in gear, give a little throttle and see if engine jumps or moves more than a very little.

Get this. The engine does move. Just pushing on the car in PARK with no parking brake you can see the engine move about 3/4 an inch. It also moves so much that you
can see where the front radiator hose is rubbing the engine cover as the engine moves.
Look at the pic. The engine is moving almost an inch and the hose is leaving a black rub mark on the plastic cover.
I showed this to the dealer when I suggested it was the motor mount. Took the service writer out to the car and said "look at this rubbing. I think the motor mounts are bad which may be causing the clunk I'm experiencing".
Nope. Motor mounts are fine, he says. Can't duplicate problem, he says. Bulls*** I say.



Anyone else have a rubbing mark like this?

I would take it to the other dealer you spoke of, sounds like your current one just doesn't want to do the work. That or take it to a local garage that you trust to see if you can get one of their mechanics to concur with you and report back to your dealership with the findings. Sounds like the motor mount to me.

Did you go for a ride with them? I have a similar issue with my 02. I ask to ride with them when I dropped it off only to find I was waiting 45mins and I couldn't wait any longer. The next day I get a call and they say they couldn't duplicate it, so I went there for a ride with them. Then on the ride they felt it before I did and said it may be from a bad mount (which I think BillBoost said a while back).

I heard the motor mount on the GXP is a pain - like 5 hours of labor or something. Someone else on the BC had one go bad. With all the evidence I demonstrated to them, I feel they don't want to do the work. I did not buy the car from them, but I have taken it to them four times in the last year for about $1500 worth of warranty work. I think they are sick of me.

I will try a test drive, but if they make me wait, or set up some screwy time that I can't fit in my work schedule them I'm outta there. I'll try the other dealer.

My dealer just informed me that mine was do to a bad motor mount. I'm not sure which one but they said it was hydraulically controlled. When they finish working on it I'll ask them which one it was.

* EDIT * Sorry it was a bad front transmission mount.