Hello everyone,

I just picked up a 2007 G35 coupe with only a little over 80k miles. I’ve only had the car for about a month and I’ve started to notice this high pitched noise when my car is idling. The noise seems to be the worst during a cold start and you can even here the ring inside the cab, once it gets hot outside the sound seems to fade away. However in the morning even after I drive all the way to work it still makes the noise. Does anybody know what this is? I’m a bit more worried since I just got the car. It’s just a very high pitch noise that seems to come from under or the back of the car, seems to not be coming from the engine. It seems to go away after I drive the car for awhile, but then it comes back after not starting for awhile again. One mechanic thought it could be the fuel pump and said to not worry about it, but I don’t think that noise is normal so I am worried!!

EDIT: I was told by two mechanics that it was the fuel pump and so I had it replaced, however this is after the replacement and the noise is still there :/. Wasn’t a cheap replacement lol and I’m pissed the noise is still there, what do you guys think this is?

 

U sure u dont have a supercharger? ☺️☺️


Raise the car up and crawl under there to try to pinpoint where its coming from.

 

Lol no super charger. Gotten a lot of opinions. Someone thought fuel pump, another thinks exhaust leak, another said trans (god I hope not), and another said belts. Taking it to an actual mechanic today, hopefully they can help pinpoint something.

 

i'll add another guess.... that kind of pitch has to be something like a vacuum leak, no? if you say it's coming from the back, maybe a cracked charcoal canister?

edit:
should have added, go to your passenger side behind the rear wheel. the canister is up under that fender liner. if the sound is louder there, i vote canister or some other evap leak back there. i don't know the evap procedure on these cars but the system probably doesn't purge all the time so maybe that's why you don't hear it all the time. but i bet it does on startup to get rid of built up vapor pressure stored in the canister.

also just realized you have a coupe so if they put the canister somewhere else, sorry. i have an X.

 

Really appreciate the input!!

 

Prolly just a vacuum leak.