So I just picked up my 996tt this week and I encountered something a bit odd today. On the highway while accelerating past 90-100MPH (didn't go much faster since the sound) I hear a high pitched whistle noise in the cabin. Noise is loud and almost sounds like its coming from within the cabin. And no, its not the sound of turbos spooling.

As soon as I go below 80-85MPH the noise goes away.. Anything under ~90MPH, even under heavy load, there is no noise.

Thoughts?


Update 4/5/2014: Video added

 

also if you depress the clutch and it goes away? it is the valve in the power steering reservoir "whining". it is commonly known. if that helps do a search on that and tsb 4897 (iirc? )

 

Front or rear is the noise coming from?

 

I experience a similar noise at higher speeds. I attribute it to gear/driveline noise and it is only apparent under the same conditions you speak of. Car is perfect mechanical condition and after "big" maintenance service change this past spring - the diff and trans fluids were super clean. There are a couple threads regarding this I believe. I just turn up the BPM or AC/DC and ride! :-)

 

It's really hard to say, it almost sound like it's coming from the dash or in the cabin. If I had to pick front or rear I'd say front.

The noise is far too loud to just cover up with music. The car is in great condition and I know it's been cared for through and through, including diff. Fluids.

 

Hmmm... my noise is so faint the windows must be up and radio off. I'd have to hear it.

 

That is a built in safety to make sure you don't drive over 100mph on a public road. Try on a road course and see what it does.

 

Check the front trunk lid fit. The leading edge of the front trunk lid should be *below* the bumper by a fraction of an inch. How big a fraction? Well, close to a quarter of an inch. Check other Turbos or other Porsches. My Boxster has the same characteristic: the front trunk lid leading edge is noticeably lower than the bumper.

 

I had a 7 series beemer that did that and it was a bad seal around the windshield!

 

He's stating that is is NOT constant though - going away when not under load (accel pedal released)

 

i have almost the same problem but starts at 140-145mph..

 

police siren?

 

I think I have the same issue. It is a loud whistle at speed.

I thought the sound was coming out of the passenger side speakers.

 

OP, is the car bone stock?

 

I had the same issue........turned out to be CHP