Macster

It was the new rear tires balance.

Finally found time to drop car off and service manager had rear tires checked and found the balance off.

Tires were rebalanced and a test drive this AM (picked up car late last night after work and had no time to drive it at highway speeds) confirmed vibration gone.

Woohoo! Smooth.

Sincerely,

Macster.

ltc

Was the imbalance due to a missing wheel weight?
Post balance, how many/how much weight is applied to the wheel?

IIRC, there is a spec on how much weight should be applied before the tire is declared "out of spec" and should be discarded for another new tire.

Hoosier_Daddy

Stock wheels?

Is it me, or are the stock TT 18 inch wheels very sensitive to balance?? Seems after a couple of thousand miles I always end up with a vibration creeping in.

ltc

Since the wheel balance should be static, then either you've lost a weight, spun the wheel on the rim (both easy to check) or have an internal issue with a tire (flat spotting, preliminary delamination, etc)

wross996tt

...or the original balancing was done poorly on a less than adequate machine. Porsche is very sensitive to balanced wheels as are most sports cars.

falcon7x7

Whatever the reason, glad you are running smooth now!

adam_

Not directly applicable, but I always have a "road force" balance done with new tires. If you have an issue that seems like a tire but static is OK, consider a road force

With new tires I've never had an issue with a tire (occasional rim bent or runout)

But recently I was mounting new PS2s onto brand new PERFECT rims and they would not 'road force'... had to exchange the tire for a new one and it was fine.

Road Force is done with a Hunter 9700 or equivalent...it essentially measures the static balance as well as the force generated on a roller against the tire as the tire rolls- so variations in tire stiffness - which does not show up on a 'balance' but still influences the feel- will be identified.

FYI

A

Macster

I don't have the full details. I received call from service manager that car was ready and he mentioned in the voice mail something about road force balancing.

Dealership was closed when I picked up the car. The service manager left car outside locked with key in trunk. I have second key so was able to drive my Boxster to dealership, park Boxster and drive Turbo home. Then late at night I called a cab and had it run me over to dealership and picked up the Boxster.

The dealership doesn't have its own tire facilities. I knew this, and had been told it used a nearby Audi dealership service department's tire facility. The Audi dealership and Porsche dealership are owned by the same people (family I think).

I've had several sets of tires installed on my Boxster -- mounted and balanced at the Audi dealer's service department -- and have never had any problems.

What I think happened this time is that unbeknownst to me the Porsche dealership had the next door Honda dealership service department mount and balance the tires. If I'm not mistaken the Honda dealer is also owned by the same people that own the Porsche and Audi dealerships.

The trouble is the balance job was not very good.

The tires were road forced balanced -- at the Audi dealership this time -- and found to be out and brought into proper balance. I do not know how much weight was required and it has been very wet and I'm unable to get out and get down and look at weights on wheel.

I will get more details Monday and if the wheels did end up at the Honda dealer I'll make it clear I do not wish my car's tires to mounted/balanced at the Honda dealer. The Audi dealership is ok, though I was in there a few months back and service manager told me he sometimes sends excess tire/wheel work to a nearby independent tire store, which I have used in the distant past and which is no damn good. Described some of the things that happened to my cars while there and he said he'd not use the shop again.

But if there's any chance the Audi dealership sends any Porsche wheels/tires to the independent shop for mounting/balancing then I'll not use the Porsche dealership again for tires if it can't assure me my car's tires/wheels will never end up at the Honda or indy tire shop again.

Sincerely,

Macster.