02 C4 Cab - Front end weirdness

In the last few month my vehicle has developed some front-end weirdness only evident above 80MPH. The symptoms are similar to when a front tire is out of balance, ie the "Flutter" in the steering wheel. I don't notice it all below 80mph. The vehicle only has 18k miles, and its still under original warantee. The vehicle has been to the dealer with the following results: 1st trip - dealer states wheels out of balance. nearly $200 later, all wheels balanced. Problem is still there. 2nd trip - dealer states front tire has tread problem. Correct front tires replaced at nearly $600. Problem is still there. Recent Trip - dealer states vehicle needs 4wheel alignment and quotes $230 for the job. 4 wheel alignment done and pricetag is actually $500. Dealer states the camber was also off and thats an extra charge. Dealer checks all front suspension for any abnormalities and reports that everything is tight and as it should be. Guess what? Problem is still there. The dealer said they have placed calls to a Porsche Service Rep, but haven't heard anything back. Has anyone else experienced anything like this? Its pretty rediculous that I've invested nearly $1300 into fixing a problem and the dealership is still unable to solve this problem. Any thoughts? Any advice?

Rims are straight and not dented right? Check inside of rims too for damage. Does the vibration only happen at a certain speed? If so, it's most likely balancing issue. What kind of balancing machine does the dealer use. Hunter Roadforce is best. I would not sink more of your own money. Go to a different dealer instead. Your warranty should cover the defective tires, no?

Thank you. They scheduled to have a regional Porsche Service Rep to look at the car early next week. Hopefully he'll be able to make sense of this. The vibration is only evident above 80mph and gets progressively worse as the speeds get higher. The rims appear to be fine. I've had this car for 10k of the 18k miles and have been very diligent with proper care. I'm a little pissed because another local dealer has quoted me $387 for a complete 4 wheel alignment (still high) and my dealership is charging me $500+. Im picking up the car tonight and plan on raising some hell. Thanks.

sounds like the only thing left is to check the run out of the wheels. I had the same symptoms you describe.....It was alignment and tires, which were worn due to incorrect alignment. The shop never did get the alignment right, so I fixed it myself...... Mine is a high mileage commuter, so the camber and alignment need to be set for that application, or it just eats tires and after 10,000 miles needs new ones. The set up I have now results in me getting 24,000 miles out of a set of rear tires (proven) and I expect to get 30,000 miles out of the front ones, based on the way they are wearing. For the rears to last that long, you have to remove all the camber out of the suspension, IE set it to zero. I did that and the car still handles just fine. I am sure the pureists will screech, but T.S., it is my car. With the front tires, after the alignment done by the shop, I carefully watched the tire wear and adjusted the toe ever so slightly every couple of thousand miles until the front tires wore evenly. Within a few thousand miles after the alignment the shop did, it was obvious that the front was toed in too much...... I don't know why the dealer couldn't get the alignment right, but they only got one chance at it......fukc 'em...My car and I are at peace with eachother......

Update. I picked up the vehicle yesterday and flat-out told them I was not paying for a $500 alignment. I explained that other local dealerships quoted me much lower pricing and that they need to adjust my invoice accordingly. To my dismay, they said "sure no problem". No questions asked. Invoice reduced to $325. (still high in my opinion). I test drove the vehicle at speed shortly after leaving the dealership. The front end vibrations is 50% fixed but still evident at 80mph, and very evident at 90mph. The dealership then explained to me that this may be normal. My response was that there is no way in hell that porsche would engineer the vehicle to vibrate at 80mph. I questioned the ability of their "porsche" tech and he's only been working on Pcars for 2 years. This may be the problem and I am willing to bet that the wheels were not properly balanced from the beginning. The dealer did confirm that they use top of the line "Hunter" machine. A regional Porsche service rep is scheduled to be onsite early next week. I'll post the verdict.

Right on. Stick to your guns and get this problem resolved. Frankly, I'd be a little pissed paying for repairs that did not rectify your problem. Talk to PCNA about this as well.

Diablo, Here are the other possibilities that I could think of. (1). Rotors out of balance, an out of balanced rotor can also cause shaking at speeds (2). Torque too low on the lug nuts, the factory spec calls for something like 95 ft lb, but I always torque them at 105. I found at 95 ft lb there are more vibrations. I have also had the similiar issues you are experiencing on my 993, the final fix was to get a on car "black magic" balance. Basically the wheel are mounted on the car and the shop uses a stand alone wheel spin machine to spin the wheel while it is on the car and the technician would place his hand on the car to feel the vibration and adjust the weight on the wheel until it is perfect. I believe there are more advance eletronic machines out there that can digitally balance the wheel without doing it by hand. This way the wheel and the rotor are balanced together and it is a perfect balance! It takes about 5-10 minutes per wheel, and it is all done by experience and feel in my case. That's why I call it the black magic wheel balance. Car feels perfectly balanced all the way to 145mph! So you may want to call around to see if there are any shops around you that offers on car wheel balance. FWIW, the shop that did the work for me is Gran Turismo East in Atlanta, GA. Owner of the shop was an ex SCCA racer.

Ok let me cover what you have done.... Aligned car (Several times) New tires (just in front?) First got a friend with a 996.....? Switch (4) tires with them....both go out...so if it fixes your and makes his act funny. Next do you have a report from the dealer of what your alignment was before and after? This vibration your feeling, do you feel it in the sterring wheel? or just feel the car shaking? While your out and the car is shaking, touch you brake just a little with your left foot (keep the gas in it....)....does it get worse? Given they have take your wheels on and off a few times I'm sure the nuts have ben covered at last once.... Ok if the above does not point you to something bad in the wheel rotation area (tire/flatspots, rims , rotors) then look for at wheel bearings...could be control arms...... But I'm a betting man....switch tire with a friend....I bet it goes away......