unclespeed

I noticed a high pitch whilstling noise yesterday on my pcar. It changes and goes from being non-existant to quite loud and annoying. It is high pitched and ends at around 4k RPMs (possible due to pitch being inaudible for human ears).
I'd noticed it a few times fince temps dropped to freezing in here in Cincy but it always went away (and was very minor).

This now occurs at idle too and seems to be coming from one of the belts. The belts look like their in gc but what do I know...and it's not like I took them off to check or anything...any thoughts on what this could be? Is it an expensive / difficult fix if it is the belts?

Thanks all and happy new year!!

TMc993

We were in single digits here three days this week and each day my power steering pump whined in sync with RPM until everything was properly warmed up. Were in the low 40's yesterday and no whining.

Terry

unclespeed

that's what I am hoping, as it was as cold here (obviously). Is the power steering pump in the rear and was your sound existant at idle?

GabiOsz

I often get a whistle from the throttle body, don't know if it's the same issue, but it's more proniunced when it's cold for some reason, it's always been there and has been there on other 993's I've driven.

TMc993

The power steering pump is located on the front, right-hand (passenger) side of the engine. The sound I heard came "over my right shoulder" and increased when I turned the steering wheel.

I am familiar with the throttle body sound Gabi described and this was different...More of a whine than the whistle of air.

Hope this helps.

Terry

jimbo3

Might be the fan belt roller. I have the same thing and the belt light has started to go on intermittently, too. Check out the diy section in p-car for details.

-Jim

Marlon

maybe a vacum leak:
https://rennlist.com/forums/showthre...rc#post4931085

J.B.H.

Same thing here...mine sounds like a faint supercharger wine...

unclespeed

well, the weather is warm and the whining is gone...Now I just have to get that da%n front windshield leak sorted ;~)

m_reagan_s

I had the same issue and searched this forum for an answer. I concluded that it was the belt tension sensor or something along that line.....there's a DYI out there that tells how to replace it. As I recall it was easy and cheap to do. Mine's gone away since then. Do a search and you'll find it. PM me if you can't and I'll search my notes.

Robin 993DX

Was your heater on when you heard the whistle sound?

It could be the vaccum operated flap for the HVAC system intake side in the engine bay. When you turn on heat the vaccum operated servo operates a flap that opens to allow more air to engine the engine fan housing pass through the engine head and into the heat exchanger for more hot air into the cabin of the car.

Sometimes the vaccum operated servos develops a leak, and that's the sound you heard.

Davies

A few years back, I had a faint whining sound that followed RPMs and drove me nuts. Couldn't figure it out. Then I realized it was coming from the radio(!). Believe it or not, changing the ground strap to the battery fixed it (actually, it was a magic fix-all for a whole host of strange electrical gremlins...But that's for another thread.) It's a long shot, but hope that helps.

jenskleis

I would have a look at the fan belt runner.

Mine (on my previous 964) began whining at idle.

A squirt of WD40 directly on the centre bearing of the runner cured the problem.

Take care,

Jens

tom97c4s

I have a whistle sound at start up which is throttle dependant. It goes away after warm up.

95 C4 993

I hear a whistle as well. Its very faint and I dont hear it all the time but for the past 5 years, its been lurking.