01_aero_s

hi folks - a new member to be board. need to discuss a disturbing find. Have a 2001 S with 13100 miles - recently noticed that at higher speeds (75 and up) the entire car shutters (through the steering wheel as well as through the seats). At first I thought it was because the top was up, but then that wasn't the case. Thought it was tire pressure, and the pressure is at 29 front 36 back (Pirelli P-Zeros).
Have aero kit - was not a problem 5000 miles ago. Anyone else have same problem? <img src="confused.gif" border="0">

Wachuko

Let's try the easy stuff - Bent wheel rims, out of round wheel rims, unbalanced tires?

craigg

Also check for feathering on your front tires - inner edge. This is a type of cupping that may not seem obvious to you. The mileage you have is about right for this to manifest - I had a similar problem. The aggressive alignment of these cars can sometimes be the cause.

Solution: new set of tires (sorry)

Sean

I've had the same problem on my 986S with 18" Sport Designs. Diagnosis: bent rim. It is unfortunately common to have a bent rim, especially if you're running low profile tires. <img src="graemlins/crying.gif" border="0" alt="[crying]" />

Ghost Rider

What you should do is take your car to a tire shop that has a Hunter 9700 machine. See <a href="http://www.hunter.com" target="_blank">www.hunter.com</a> and do a search for a dealer in your area. My local Goodyear tire store has one and it correctly identified both a slipped belt on my original Pirellis causing vibration at 75mph (could be you have the same problem) as well as their machine identified an out-of-round brand new Bridgestone S-03 tire from TireRack.com.

I highly recommend checking out your wheels and tires on a Hunter 9700 as it will identify out of round wheels, out of round tires, etc.

I suspect you'll need some new tires, but without getting checked on a Hunter 9700, it is hard to say.

Boxster 3.4

Second on the Hunter 9700. Don't waste your time at a shop without this equipment. Find one on the locator give the shop a call and get the front wheels (and maybe rear as wel) looked at and that will get you one step closer to the answer.

01_aero_s

Thanks for all the tips guys...knew that was the case, but wanted to see if it could have been something else... better ease up on those corners I guess....