I posted about this in my other thread, but figured I'd create a separate thread on it since it's effectively a new issue.

I am hearing a slight whine/grumble at low RPM inside the cabin that increases slightly with throttle application. The noise is present only after the car is warmed up, and is not dependent on the clutch being engaged (i.e. it's there under load and not under load). I was thinking exhaust leak, but I had the car up on a lift and we couldn't find a leak anywhere.

HEre's a vid:
Any thoughts on what it might be?

Here are things I've looked into:

- Drive belts and pulleys - replaced the drive belts last week and pulleys all sounded quiet and rotated freely
- exhaust leak - can't find one
- Climate control fan - the noise doesn't change even if I turn the climate control completely off
- radiator fan - noise seems to still be there even with the fans not running. I have the electric rad fan, obviously.

Maybe something loose in exhaust somewhere (installed Tanabe y-back in July)? Seems unlikely...

 

Sometimes l hear the clutch on the compresser on the ac unit engaging when on.

 

Need to hear it from the outside also, if it's exhaust, it will be louder.

 

Gman- the sound is there when the AC is on or off. Doesn't seem to be dependent on AC or climate control system. Seems rpm related.

Texassscout - there's no appreciable additional loudness outside the car other than the exhaust, since it's somewhat subtle, but I can try to grab a vid tomorrow.

 

Open the hood have someone give it alittle gas while you listen.that might help.you isolate the sound.l know my ac clutch drives me nuts when l hear it.

 

Update: Dealer found the issue - it was the Fuel Pressure Regulator (FPR), for which there was apparently a TSB a while back. Changed out the FPR assembly (includes a fuel hose) and the noise is gone.

https://g35driver.com/forums/engine-...ml#post6029054

https://g35driver.com/forums/engine-...mper-help.html