kpmd2000

For the past few weeks, I have noticed that when i press the accelerator, i hear a faint high-pitched howl from the rear. It is independent of gear and speed. Performance seems to be unaffected, but it's driving me crazy! Any ideas?? thanks

LexVan

Year & mileage?

Hurricane

I had that same problem, but only when my mother in law was in the back seat.

kpmd2000

13 c4s 23k. it sounds like a high pitched 'hoot' lasting about a second or two.

CSK 911 C4S

Might just be the throttle plate opening getting ready to suck in some nice chilly air up there in Chicago.

Code

Is your A/C on? If so, next time you hear it turn it off and see if it stops. Some people, including myself, experience a whine coming form the A/C compressor.

kpmd2000

compressor is not on. maybe the throttle plate as you say, but it didn't happen last winter and it hasn't been very cold lately and it's getting louder

Benedict14

Yeah, I'm pretty sure that I know what it is. I'll have to look up the exact nomenclature, but the culprit is the oil cooler vent valve. Long story short, I got the following responses from the dealer:

1. "That's normal", then

2. "I test drove some other cars and they do it too", then

3. "Oh yeah, I found a campaign on it. We'll replace it".

Number (3) only occurred after I found it right here on Rennlist. Good news is, it's no big deal. If I don't post again on this thread then the name of the offending part is correct.

CSK 911 C4S

Does that campaign have a number?

Benedict14

Update. It was the oil separator. Apparently there's a vent in there that creates the noise. No, I don't have a campaign number. Maybe it was a service bulletin ? This was two years ago. That's a lifetime in my world

I do have the invoice though. "Replaced oil separator". Search for this thread - Glass Sunroof Rattle and Whining Motor Noise

hobbs

I have 2014 C2 with same noise. I will have the dealer check the oil separator. Thanks