Vibration while accelerating

Your first thought is most likely the problem. You say the vibration changes with speed. That tells me that it is not an engine or transmission problem at all. If you had warped rotors it would vibrate upon braking. The other possible problem could be tie rod ends but the tie rod ends will occur most likely more steady and on braking. It would be a good idea to have your tires balanced at a cheap price to find out if that is the problem or not.

Hi Smurfman.

Did you ever figure out what this vibration problem was?

I am having the same problem exactly. So far the GM dealer diagnosed it as a front bearing. That cost $500.00 and was wrong. The Goodyear dealer diagnosed it as a bad tire. That cost $500.00 and was wrong. Mr. Transmission thought it had to do with the engine and suggested I change the Mass Airflow Sensor as the check engine light was on and that was the reason it was on. That cost $550.00 and was wrong but was needed anyway. It started leaking a little antifreeze at the center head and cylinder head at the back bank so a friend recommended his mechanic. He did turn out pretty good and he changed the intake manifold, supercharger and valve cover gaskets. That cost $700.00 and did not do anything for the vibration. This mechanic thought the engine was sucking air threw the bad gaskets and figured the vibration would be corrected with this repair as well. It didn't, Although I have full supercharger boost back that I did not even realize that I had been loosing. I have also had the front control arm bushings changed and the front end all checked out. Apparently it is okay. The brakes pads, rotor, calipers and flex lines were all changed within the year and have less then 20,000 on them.

As you can tell, I have $2,200.00 invested in trying to solve this vibration and all I have managed to fix are a few others things. It actually puts me in a bad mood just driving it. I would really like to destroy it and collect the insurance but I do not have the demeanor for that.

Please share you experience with me!

Bill

Your axles could be the source of your problem.

Did you found the actual cause of this problem?
I have the same prob here.

Most likely CV axles. I am having the same problem that is what it is. It will keep getting worse and worse until they are replaced. I did both front bearing and mine still does it.

A bad CV joint will make the whole car shake under torq this is one of the in board joint on the CV axle, sometimes it will not do it until it has been driven for a while.

2000 GTP. Having the same problem. Wicked shimmy making it un drivable and unsafe at freeway speeds. It is not side to side more like a bounce up and down on freeway speeds over fifty under load on acceleration. Smooth as silk when it not under load or in town. Broken motor mounts will cause this problem as well. Midus in Redding California worked on my problem but still it is unresolved. Changed motor mounts, tie rods and all four struts plus a fluid change in brake system costing me. $2,375.00. I brought it in for this problem and they fixed everything else but what I brought it in for. Midus said it was a list of possible things. Torque converter sticking, Supercharger belt system vibrating and some reasons even an idiot would know better. But the bottom line is they just wanted to take more of my money. Hell of a way to get return business I would say. Part changers. Not real mechanics that work the problem those days are gone.

Did any of you ever get anything figured out on what the problem is? My 2000 Grand Prix GT does the same thing. I have changed the inner and outer tie rods. I have new motor mounts. I have new transmission mount. I had the front end checked out. My tires have been balanced and I have had it aligned and I still have the vibration when accelerating. It is more like a thunk vibration with tire rotation I guess, but it does not do it all the time. It does it every once in awhile but it i's bad when it does do it and it is daily. Please help.