I have had my 991S for two years now. After my recent two year service I have noticed my car make rather noticeable and random steering directional changes. Happens every few days. The car despite my two hands on the wheel will quickly try to swerve in one direction or the other. It's rather unsettling. I'm not sure if this is related to the electric steering in any way. I ask if others have experienced anything similar. I don't have a local dealer and I'm sure when I drive 100 miles to the dealer they won't be able to reproduce it. The car alignment seems ok when I let the steering wheel go etc. thanks for any help.

 

A serious steering issue vs. 10o miles to dealer....

I think the drive to the dealership wins.

Steering should not exhibit that trait when it previously did not. be safe!

 

I would call Porsche roadside and have them put the car on a flatbed. I have no experience with this, but control issues should be taken very seriously. The car can be replaced. You cannot.

 

+1 on that!

 

Do you think it is steering or torque vectoring?
One would hope a code would be set if the steering was malfunctionimg that way.
It could be a battle with the dealer otherwise.

 

had similar issues, could feel it on the steering wheel as a pulling to one side then a correction. ended up being a small leak in the tyres and the electronics kicking in. have a dealer look at it.

 

Had similar experience in the past. Turned out to be a screw in the tire. Tire pressure was too low in one tire.

 

Thanks for all the responses. Will get the tires checked locally then get it to the dealer if issues not resolved. I will report back here as to what the issue turns out to be. Thanks again

 

I agree with others --- this is not a trivial issue to be concerned about! Considering all the electronics involved, you could suddenly find yourself in a very scary situation if this goes unchecked! Also, do some more searching, including other forums. I ran across a thread recently in a European forum called 911UK and this very symptom (car veering) was discussed. (Sorry to Admin - I normally wouldn't cross-post to other boards, but in this case I want to make sure the OP can quickly find this important discussion!)

Several theories were discussed in that thread, including low tire pressure, brake caliper binding, etc. but in the end it was posted that the resolution was the replacement of a "power steering unit" whatever that might be nowadays. Maybe a computer, maybe a mechanism....

I would call Roadside Assist and get it hauled out.....

 

is it PSP or regular steering?

 

I think I understand why you would ask this, but if I recall PSP is "physically" no different than what you call regular steering. PSP is a software upgrade, isn't it? Steering on the 991 is all electronic I imagine, regardless of model.

But maybe I am thinking of the GT3 steering tweak discussed in other threads.

I do have PSP on my C4S.....

 

Yep, I just asked as a datapoint . Understand the differences.

 

I had the same issue and it was related to tire pressure being low -- it seems like 4-5 PSI low can trigger some strange behavior with the steering.

 

Based on what you describing it doesnt seem like a nail in tire etc since it would pull and he currently states alignment is fine. It wouldnt be PTV since that has to do with rear braking. Does it happen on certain roads or randomly? I would have it checked.

 

Had similar problem and it turned out to be caused by an internal steel belt that was beginning to separate from the rubber in one of the front tires. There was no external evidence that this was happening but fortunately for me the service technician recognized the steering wheel twitch symptom.