So I had my '04 GT3's rear main seal replaced due to some oil leak about a month ago. I had the local dealer do the work as the car is a CPO and still under warranty. After the engine and trans were reinstalled and the car was back in my hands, I noticed a faint whine or whistle sound at higher RPMs. It has the same sound as when a non resistor spark plug is put in a car and you hear the whine sound through the car's stereo system. In fact, I had the plugs replaced at the same time so my first thought was just this. But it happens even with the stereo off (I never use it anyway). My other thought was that there was a vacuum leak but the engine was performing well if so. The sound also appears to be slightly louder when the engine is colder but it still persists even when properly warm.

I took the car back to the dealer and took the mechanic for a quick drive. He verified the sound was there so the car was left for him to see what he could find. After two days of searching including removing my aftermarket air filter and replacing it temporarily with a stock unit, removing the ancillary drive belts and listening with the car on the rack, they couldn't determine where the sound was coming from.

So at this point, I am to keep driving it in the hopes that something will change, pointing us toward the culprit. Not an ideal situation but I guess the dealer is unable to proceed otherwise.

I am curious though if anyone whose had their RMS replaced has had a similar noise arise after. Could it be that the seal itself is passing air into the motor under high RPMs and this is causing the whistling/whine sound? This considering the crankcase vacuum. Any other ideas as to what could be causing this? While the new "turbo sound" is interesting, I'd prefer to eliminate it.

 

Interesting, I have the exact same happening to me.
It's only at idle and not all the time.
It seems to be coming from the front left. Maybe the speaker? maybe not?

Also, if I slightly engage the clutch, it goes away...

Let me know if you find out what it is...

 

fotostars,
Thanks for your information. It may be possible that your noise is throw-out bearing related. Especially if by depressing the clutch pedal, it goes away. Why this would appear to be coming from up front though is odd. Although, I know these kinds of noises can play acoustical tricks as far as location origin.

With mine, the noise remains the same whether I hold the clutch in or not; whether in gear or not. No one else experience this post-RMS work issue? Any other suggestions as to possible culprits?