Just noticed today that my '02 996TT (9k mi) has a vibration at 70+ mph.

Odd that I just noticed it today - here are the two recent changes to my car that may be related:

1) For the first time I bumped up the PSI in the P-Zero's to manufacturer recommended (36F and 44R), and

2) I brough it into the dealer this morning for oil change, smog, and to check a slow leak in the right rear tire. Dealer came back and didn't comment on slow leak but said that the rears are down to wear bars and need to be replaced. End of story.

Drove the car home from dealer, without new tires, and notice vibration for the first time ever. What gives? I dropped the pressure in the tires back down to low 30's (where it was when I bought the car 1k mi's ago), but vibration still appears...although more subtle.

I know that these cars, especially with Pirelli's, can have vibration issues, but I can't figure out why this would pop up today. Couldn't be related to service performed, could it?

Any ideas?

Thanks in advance..........Rich

 

Rich,

You probably have a mild case of tread separation in one of the tires (or more... but unlikely).
If your tires are really down to the wear bars; replace them.

I'll bet when you replace the tires and have everything rebalanced (dynamic balance) you will be fine.

Joe West

 

By the way... if the dealer removed a tire from a wheel for any reason (such as fixing a leak) and failed to rebalance the assembly after the tire was put back on the wheel; it could cause vibrations.

The tire and wheel are balanced together... and when you rotate the tire on the wheel, you can throw the balance off and cause vibrations.

This may answer your question as to why the vibration started after you visited the dealership.

Joe West

 

Problem solved!

Replaced rear tires and re-balanced front. Ends up I had lost a weight on one of the fronts.

Thanks for all of your input.

- Rich

 

Did you have the new package road-forced balanced? That's the best way to get a good balance job.

 

I just had the dealership do it for me. One stop shopping of the tires/balance and alignment. Funny enough, it ends up they ordered the tires from the same place I would have - Tire Rack in Reno.

Next time w/ all 4 needing replacement I'll do it non-dealer - Tire Rack w/ local road-forced balance.

- Rich