I love driving my box, but only at lower speeds, ie below 60mph or so....
My box has been stricken with the dreaded steering vibration issue and yes I have gone through a number of the similar post here.
Have gone through 2 workshops, got the car tested by a specialist that drives like a race-car driver... And everyone tells me my car is nicely balanced and setup - indeed he was taking corners at sharp speeds (but not on highway) which I never thought possible and the car just takes it in its stride.
However, I can't get them to test the car at higher speeds... esp above 90mph on less than perfect highways... (which unfortunately is what I do when I travel interstate).
The steering vibrates quite a bit at that speed and above, if the highway is less than perfect. So much so that I have to back off on the accelerator. It's a shimmy vibration and sometimes on rougher roads, the steering rocks left and right. I've tried letting go of the steering and although the steering rocks left and right, the car seems to track straight.
So far, I've replaced all 4 rims as one of the front rims was badly dented over 2 axis (left right, up and down), the other front rim was slightly out of round. Which leads me to believe the car has taken a serious pothole before.
Alignment done 3 times, and wheel balancing done 3 or 4 times, with once, on-wheel. Unfortunately I can't locate a hunter balancing anyway here locally.
The wishbone, control arm link, drop link, tie roads all seem ok. Those components being tested with a rubber mallet and checking for free play. Are there any other methods to definitively test whether they're failing ?? I was told the wheel bearings were ok.
The front brake rotors are thin and my mechanic suggested that I replace those as under some rare chance, they may cause vibration (no vibration under braking though), which I agreed to since they are thin anyway.
I'm also going to change the suspension to M030, to try to get some extra stability as I find no much confidence taking highway corners at speed. Seems twitchy and steering gives me no confidence it's going to track around the corner.
Brakes and suspension not done yet as I'm waiting for the M030s to arrive.
Anything else I should check ? Alignment shows everything within range, no sign of bent chassis or suspension components out of whack.
I was also told by the "race-car" mechanic that the vibration is due to the "excellent" steering feedback of the boxster. There seems to be much less vibration on smooth roads. But it would seem excessive if I have to back down on the throttle sometimes to below 80mph to feel confident of the car. ANd that's on slightly imperfect roads and not broken roads. The same roads which my VW Scirocco just flys through at well over 120mph (but then that car has an electrically assisted steering which give very little feedback).
I do remember the first week when I first got my car, it seems to take corners very neutrally, now it seems to initially understeer and quickly transitions to oversteer as I add more gas.... All with the accompaning vibration... Makes taking corners at speed pretty hard work to find the right balance.
The car is a 9 year old with very low mileage - less than 20k miles when I first bought it and since then I've already added 3000 miles in less than 2 months. Maybe this garage queen is not used to be being driven hard...
Sorry for the long post... I'm just tearing my hair out...
Any suggestions on what else to test or other more definitive testing methods, I'm pretty sure something is not right but not broken enough to be obvious.
Oh... one last piece of observation - when I first got the car, the suspension felt pretty pliant... rides over broken roads nicely, now it just thumps and rumbles over the same broken road - could the shocks be on their way out ?? Or is the stock boxster suspension pretty stiff ?? When I press down on the fenders, the front suspension seems softer than the rears, is this normal ?? Rebound of suspension feels normal though, just one time up and down.