Hello all. For the past two years, I have been chasing a ghost in my car. The problem is subtle, but infuriating. Basically the car feels unstable at speed, and nobody can figure out why. The faster you go, the worse it gets, and I recently moved to Germany which makes it much worse. Three different Porsche Specialists have looked at the car now, none have been able to tell me what they problem even is.
For a little history, when I first got the car, one of my favorite things about the driving experience was how unflappable it felt at speed. It tracked like a laser, always going exactly where you pointed it and following that line as if on rails, even over bumpy highways. One day, a few months after purchase, I was driving home from a visit to family, which was about a 2.5 hour drive. The car had been perfect on the drive up, and nothing of note happened on the drive back, except the car suddenly felt like it was moving around under me all the time. I thought some wind had kicked up, but when I stopped for gas, there was no wind whatsoever. basically it feels as if the car is tram-lining, but it does this all of the time, even on pristine fresh poured pavement. In fact it is most noticeable then, as other inputs are filtered out. The feeling is as if the alignment were randomly shifting around. It's mostly felt through the hips. At 100 mph, it feels as if the entire car is shifting nearly a foot in varying directions, at random.
This problem has now remained with me through countless attempts to correct it. During the first attempts, the only thing they found was slightly worn front LCA bushings, and a worn motor mount. Those were replaced with no effect on the problem. Next they found that the rear shocks were worn out, so the dampers were replaced with Ohlins R&Ts. Unfortunately the first set of R&Ts had a bad damper out of the box, so eventually they were replaced. Problem is still there. I started going through all of the suspension wear items. Rear anti-squat arms, rear LCA bushing replacement, new toe control arms, even tried solid ones with heim joints. Problem is still there.
Next, the car got shipped to Germany, and as some might already be aware, was severely damaged in shipping. The second set of Ohlins were destroyed, and replaced with KWv3 as Ohlins isn't available in Germany and as such are not TUV certified. The steering rack was also damaged and replaced, along with the tie rods, and associated hardware. Problem is STILL there.
So, at this point, basically the only things in the entire suspension system that have not been replaced are the front anti-dive links, and the anti- roll bar equipment. Mechanic swears they are good.
One odd item of possible note. Recently, something seems to be happening with the driver's side CV axle. The outer boot started leaking, but I couldn't find a hole in it, so I replaced the clamp, as it was leaking out through the clamp itself. Mechanic checked CV axle and says function is perfect. Oddly, the wheel carrier on this side seems to be having some sort of issue as well. The hub-centric portion has changed size slightly, with the wheels BARELY fitting over it anymore. They also don't want to come off after finally being worked into place. It feels to me as if this piece has been warped by heat somehow. Bearing on that side was replaced out of an abundance of caution. No change.
So, I am begging, someone. Anyone. Help me out? What they freaking hell is this? It's driving me insane.