First off, thank you for taking the time to read this and thank you for any insight!

Second, I know it is hard to diagnose noises over the internet, but any opinions on what it might be, suggestions on what to check, pointers on how to further diagnose the noise, etc... are greatly appreciated!




My car is an 03 turbo with 5xxxx miles on in. It is bone stock mechanically and never modified according to service history from the previous 2 owners.

Fortunately, it is covered under CPO, but I won't have a chance to bring it in until next weekend at the earliest. I was hoping to gain some insight before then.

The issue: Under deceleration in 1st and 2nd gear there is a faint, high pitched whining noise. It is possible that the noise exists in other gears, but it is hard to hear over the road noise. I can only hear the whine when in gear and decelerating between 2200ish rpm and 1400ish rpm. If I let the motor wind down lower (still in gear), it seems to get more faint. The noise goes away if I push in the clutch.

Description of the sound: As mentioned, the whine is very faint and high pitched. It almost sounds like an electrical whine, but there is definitely a metallic (not grinding or scraping, perhaps almost squeeling) quality to the noise.

It doesn't sound like the typical chirping sound that a failing throw out bearing makes. The noise sounds like it might be coming from the front of the car (although this too is hard to pinpoint). So perhaps the front differential?

What (little) I've done to diagnose the issue: I did search a few threads concerning the front diff, and some folks mentioned a faint high pitched whine. I tried to take some video, but the whine is drown out by road noise

It does not sound like a wheel bearing, but I jacked up both ends and checked for slop on all corners. It all seemed fine to me.

The first time it happened (not long ago) it was very faint and not repeatable. I checked the calipers and pads for any pebbles or sticking at that time. I didn't notice anything. Since then, it happens almost constantly when coming to a slow stop while engine braking in gear between the mentioned rpm range.

Any ideas?

 

Its your Pentosin reservoir... next to AC.... its probably low.... there is a recall on the actual unit....

 

Probably what Markski said

Mine was due to a bad clutch accumulator (also a common, but cheap to fix issue)

 

Another possibility is leaking front diff. Once it gets low on fluid it will make metallic screeching noises at low speeds.

Edit: I see you already thought of it. You can see fluid on floor if it is really leaking.

 

Thanks for the quick replies!

The motor is still warm (got done driving it half an hour ago), so I ran out to the garage and checked the pentosin level. It is currently at the low mark, and halfway to the high mark... if I'm reading it correctly. Here's a crappy pic showing the side marked high and max:



MBailey, if there a dipstick for the front diff? I may have completely missed it, but I couldn't find where to check the level.

thanks again!

 

you have to have the car running and warmed up... then check the dipstick...
should be on the HOt high level....

 

I'll check again tomorrow and report back.

Thank you for potentially saving me a trip to the dealership, Markski!

 

Sorry to hijack the thread, but does anyone know why my car make high pitch noises when I get my car up to about 120mph?

Does it have to do with the moldings or exterior parts?
I just found out after my car was flashed. Please help.

 

idget, the symptoms you describe are actually what is going on with my car so I hope you report back with positive news.

 

I've got the exact same "problem" (it's not so much of a problem as it's neither really loud nor sounds dangerous )...

 

Does any1 having this problem have a car w/ a Tip or are they all Standards?

 

yes, pentosin issue. i had exactly the same. recommend gt2 slave conversion

 

My power steering made the same noises at low speeds, I was low on fliud, when I turned the steering wheel the noise got a little louder? FYI..

 

Does the noise go away when you push the clutch in?

If so it is a valve in the pentosin reserve that vibrates and creates the noise whne hot- clutch releases the pressure and it goes off. This is a warning sign.

Needs replacing. Common fault, Porsche service bulletins on this

 

OP states and the same for me, the noise stops when the clutch is depressed.