my 991.2 c2s is equipped with both, rear axle steering as well as front axle lift, recently a handling imbalance has crept in wherein the car gets twitchy as speed climbs over 60mph, it no longer feels as sure footed as it felt earlier. the dealer feels it might be a wheel issue as a wheel may have hit a pothole, but he cant really pinpoint wheel damage. another issue i have reported from the from the beginning is an occasional light clunk sound from the rear, like from a worn CV joint. but the service manager can find nothing wrong.
the car has done only 6200 kilometers( less than 4000 miles) , and im stumped as to what could be wrong. the tyre pressures are ok. anyone else facing anything similar?

 

What kind of tire are your running and what size?

Is it swaying around?

 

standard 20in factory wheels shod with Pirreli P Zeros. well, i cant really explain it, its not that the tail is stepping out, but it does try to shift lanes and the steering needs correction to keep it straight. something like an aircraft in turbulence.
once the front axle lift failure light came on and the dealer checked it, but again found nothing, and the light didnt come on again. could it be the electronic differential? thus the occasional clunk?

 

Did you let one of the mechanics from the dealer drive it at speed? Did they experience the same problem?

 

I feel stupid saying this - but maybe it needs an alignment?

 

or the road......

 

Hopefully they removed the blue suspension shipping blocks during PDI.

Yeah on an alignment check.

May need to do run-out on the wheels to find potential damage.

 

Same roads as always, they claim to have checked alignment and balanced the wheels. But I have a feeling they will discover the problem once warranty expires in June.

 

If they find a solution afterwards you'd have good grounds to get it fixed under warranty since you've established it as a problem before warranty expiration. I'd suggest asking for a mechanic ride-along so you could show them the problem under the conditions it happens for you. I had to do this once and it helped the mechanic understand what I was talking about.

I wonder if the rear-wheel steering mechanism could be damaged and causing the rear toe on that side to shift when it shouldn't due to the pothole incident.

 

You are a brave man to be driving a 911 in Delhi. Being familiar with the city, my first thought was roads but you know where your are driving.
Could be alignment or that the wheels have not been balanced properly. Uneven tire wear could also explain the wandering feeling on the road.

 

When I read "occasional light clunk sound from the rear," I thought about a loose rear upper strut mount. I've read on this forum that a loose rear upper strut can create that sound, although it would not be a factor in affecting alignment settings.

Aside, I have spent months in Delhi, and I, too, find the thought of driving a 911 around Delhi interesting and kind of crazy. The animals (bulls, camels, dogs, etc) on the road, the big trucks that break down and get repaired right there in that lane, the drivers going the wrong direction, the sudden off-road adventures that pass for exits...The Greater Noida Expressway is a nice, wide interstate-type road, but it doesn't lend itself to long, fast, carefree drives.

 

 

 

 

This sounds silly, but also keep in mind that the wider the tires, the more the car will want to move left-to-right across uneven road surfaces. It can even be something as simple as applying a bit of throttle and feeling the car want to pull in a specific direction. While some people rip on the electric steering in this car, it's actually rather communicative compared to most EPS systems.