When I received my car new, I thought I was feeling a bit of vibration in the rear when reaching about 200 km/h.

Today I was driving again and noticed the vibration quite strongly. It starts at about 175 km/h and becomes quite strong at above 200 and stronger the faster I go.

Actually to the extent that above 210 km/h the car starts to feel unstabe as if it starts to swerve left and right at the back.

Actually becomes so itchy, that I have to ease of...feels a bit scary.


What could this be ?

I called my local Porsche engineer and he said 90% its rear wheel balancing.....


I doubt, thats its drivetrain related, as I tried to go above 200 and then shift my tip into neutral....vibration remains till i deccelerate to below 170 or 180.


Any clue or thoughts ???

 

Definitely rear wheel balancing.

 

Balancing!

Take it to a reputable tire place and have them run a full test with the Hunter GPS9700.

 

Sounds like its a wheel balancing problem. If you car is relatively new (under 2000 miles) Porsche will align the car on the house. May as well take advantage of that too, if you are taking the car to your dealer. It can't hurt.

 

Sorry to bring up an old topic.. at least i search before i post!


-I have the exact same issue as described. Exact speeds as mentioned.

-I just changed front and rear tires by a reputable tuning & suspension shop.

-I still have this high speed vibration and it becomes scary going past 200 km/h.


Either my shop did a bad job at balancing.. or there is something else.

 

When tires are mounted, regardless of the shop's skill level or equipment quality, and particularly if lots of soapy bead lubricant was used, the tire(s) will sometimes rotate about the rim slightly, which obviously whacks the balance. In my misspent youth, I was taught to drive the car hard (easily convinced) for the first 50-100 miles, being sure to include several maximum effort stops (without lock-up) after balancing. Then, back to the shop to check the balance and re-do as needed. About one out of three times, re-balance was needed, for at least one wheel/tire. I always told the shop my plans, and none ever disputed the wisdom of the scheme. Since they realized I gave a damn about my car and tires, they were coopertive, and never hit me too hard for the re-balance. Hope this works for you guys.