Is it possible that the brake rotors aren't balanced? THe show on spike said that could cause vibrations...

Not sure which mount would be the most likely candidate. To determine how much movement is normal you may have to do a "stare and compare" with a similar vehicle that doesn't have the problem. Put it under load and watch the movement of the engine. Does it evenly strain against the mounts when you load it, or is there a little slack. Get as good a look at the mounts as you safely can. You may have to enlist a trusted helper to give it the gas while you observe. The thing that I find most curious is that it has had the problem to some degree since you got it with low miles. If I understand correctly, the vibration seems to be vehicle speed dependent, not engine RPM dependent. Since you shifted into neutral during an occurence and the vibration remained, it would seem to confirm that. But since the problem seems worse when climbing hills the engine load/torque appears to be a factor. You have already covered the usual suspects. Not sure where you go from here, but it seems worthwhile to check the mounts. Once again, my opinion, worth price charged.

Corvettecrazy, the rotors are brand new. I have gone through several sets of rotors on this car without eliminating the problem. Red, I am going to check out the mount situation tomorrow. What is odd is that I don't have the most vibration flooring it (which I would expect if the mounts were bad and the engine was shifting the axle angles). At really high speeds my vibration is gone as well, which still seems to point out that my problem is rotating. My friend has a 97 SE, which I can use as a comparo to my car. I may actually have my friend drive my car on the highway while I drive his car next to him, to see if I can spot the wheel that is shaking. The vibration is so bad, making the hood and dash shudder, that I would think I'd be able to see a wheel spinning out of true if it is being influenced by a driveline imbalance.

I am posting a couple of links with some information on "road force balancing". Seems like static and dynamic balancing are not enough in all cases. If you don't find anything else that could be causing your problem, and your alignment shop hasn't already done it, you may want to find a shop with the Hunter machine and give it a try.

http://www.sullivantire.com/xcessorize/hunter.aspx

http://www.redwoodgeneral.com/balance.htm

Just a thought.....I remember reading somewhere that aftermarket rear drums on the H-Bodys are not always balanced right. I know you said it'* in the front end, but are you 100% sure? Does the steering wheel shake or does it just make your butt vibrate like crazy?

Worn motor mounts can cause the motor to be off center in relation to the engine cradle/lower control arms....this can cause one axle to be compressed and the other side to be stretched,,,causing a vibration at speed....i just went through this with a caravan,,,,there is a spec for measuring the length of the axles from the inside of the inner boot to the inside edge of the outer boot....Im not sure if pontiac has this spec however...my 97 se has a vibration..and also a sloppy transmission mount...could be related....let me know what you find out....

The only place that I've been in the Philadelphia area that I found that you can drive over 70 is out by the airport on I-95 or in the Wilmington, Delaware area.
Best of luck finding the mysterious vibrator.
And I hope you don't succumb to either drugs or alcohol as a last resort.

202 bypass up where 611 and doylestown meet. Rarely patrolled.

I don't mean to get way off topic here, but outside of Philly (especially north) has some really nice places to see. Doylestown & New Hope are two of them.

Now back to our program which is already in progress

I have the same vibration...maybe you can come see doylestown or new hope and visit me


I have tranny problems someone could feel and see what they are