Hi,

I have a 2007 997 Base Carrera manual, 42K, well maintained. When turning left (and only left) a good amount, there is a high pitched squeal or long squeak (kind of like rubbing your finger on the rim of a wine glass) both turning in and when the wheel returns to center. If you do a slight turn to the left or anywhere to the right it doesn't do it.

I brought the car to the Porsche shop, and after a long day of driving in warmish weather it wouldn't do it for the tech. I did have all 4 corners of the brakes changed in the last 500 miles (rotors and pads).

Any ideas?

Thanks,
Jason

 

Why didn't you reproduce this for the tech? Did you observe his technique and did he do everything you did under the same conditions?


Couple of things:


Are you turning the wheel to full left lock? Is the vehicle moving when you do this?


While you can turn the wheel full lock if you do it the power steering system may make noise or possibly the belt could slip as the load at the pump is high. (FWIW, While I might turn one of my steering wheels to full lock I only have the wheel at full lock for as short as a time as possible and I never let the engine for any length of time while the wheel is at full lock or even partial lock.)


So, is the serpentine belt original? If so it might just be worth it to replace it -- if it is due on time or miles -- and get that out of the way. Even if it isn't the cause of the noise if the belt's old or has lot of miles on it it needs to be replaced.


What's the power steering fluid level like?


A sort of test of the power steering rack is to on a vacant parking lot with room at slow speed make a U-turn. As you complete the turn turn loose of the wheel and let it find its center. Note where the wheel stops. Do this U-turn several times in each direction at the same speed. If the steering wheel doesn't return to the same place every time the rack may be going bad or has gone bad.

 

Hey Macster, I've been a long time fan of your posts and how you generously share your Porsche wisdom, thanks for the reply!

I tried to reproduce the sound when I brought the car in to the dealership. I was driving the car and the tech drove in the passenger seat. Of course because I was there, I couldn't make the car make the sound.

The Serp belt was changed last year when I did the 6 year maintenance. I haven't checked the power steering fluid and I don't know how. Is it easy?

The problem isn't at full lock, it starts about halfway (either turning in or out). I did however notice it doing it when turning right, although much quieter.

I'll find a parking lot in the next couple of days and perform your steering test, I'll let you know what I find.

 

Before you do any further testing check the power steering fluid. How to check this fluid level correctly should be in the owners manual.


The fluid is or should be Pentosin so do not get any on your hands or on paint or rubber, or anywhere actually.


The only time I'm aware of the power steering system (primarily the pump) gets noisy is when it is low on fluid and the biggest cause of this I'm told is a high pressure relief valve fails -- in a power steering line -- and routes too high pressure to the rack. This forces fluid out past the rack seals but there may not be any leak sign as the rack dust boots catch the fluid. (I watched a tech remove one of these boots with fluid in it and it popped and sprayed fluid out. He had a rag covering the boot though so just the rag got messy.) But with or without leak sign the power steering pump fluid level goes down and the pump gets noisy.


If this happens generally it is too late for the pump, so a new pump, a new line (with the new valve), and new rack are required.


If the fluid level is ok then you need a tech to help you pinpoint the source of the noise. This requires that you are sure you can reproduce the noise on demand.

 

Jason,
Assuming your PS fluid is topped off and you still have the noise can you try it with the engine off? That might point to the upper strut bearing going bad.

Good Luck,

Rob

 

Hey Rob, thanks for the reply. The fluid is at the correct level. The squeak has slowly been getting worse. It is definitely coming from the drivers side, you can hear it in the car pretty well, but you can definitely hear it outside of the car better. Thanks for the tip on the strut bearing.

It is a little frustrating that it is an intermittent problem. There are times when it is fine, and then others when it squeaks/whines. It seems like it is louder when the wheel is returning to center (mostly happens turing the wheel left).

I'm guessing it is a worn rubber part, I know the 997 suspension pretty well at this point. I'm waiting for it to be a constant problem before I take it in.

I'll see if I can turn the wheel with the engine off and no PWR steering. I appreciate the reply, I'm open to any ideas at this point.

 

I have the exact same problem, and have replaced the tie rods, intermediate steering shaft, and steering column (thank you aftermarket warranty). Any leads yet? My techs next guess is also strut bearing...

 

I finally got it figured out!

It was a worn ball joint in the Lower Control Arm (Wishbone) (P997-341-053-04), they found the squeak with a stethoscope. Parts and labor came in around $700.