taiwandiao

Notice a high pitch noise coming from the engine bay in my '94 GS-R. I hear it intermediately, with and without A/C fan being on.

The best I can explain, it sounds like a high pitch whistle (or blowing into the top of a glass bottle). Hope that makes sense

I ruled out the radiator fans, as I have disconnected both to test, and the sound still persists.

Car has 150k and has just completed a wp/tb, drive belt, and ac belt change a month ago. Engine is mostly stock with the exception of DC headers that I installed last week (I had this noise before the header install).

Any ideas what this can be?

vtaker

make a video if you can. it could be almost anything.

jdmlove2006

air leak..? jet engine warming up..? lol most likely nothing I hear new noises every other week in all the cars i drive

dudesitsjdm

Do you only hear the blowing noise while driving?If so roll up your window.

taiwandiao

Will do.

That's what I'm guessing as well, it comes on and off intermediately so I really can pin point what the cause is. It's just really high pitched and comes and goes, thought someone might have a guess to what it is.

That or turn up my radio?

taiwandiao

Heard the noise again while parked, sounds more like an air leak than anything else. Aside from my intake, are there other areas of the engine I should check?

I did notice the sound to be more pronounced right when I turn on the A/C system, but goes away in about 2 seconds or so.

Teggers

If you have an aftermarket intake, a whistle at certain rpms is typical.

I have a similar noise, and although I haven't confirmed the source, I suspect it's the alternator bearings going bad because it's coming from that area of the engine.

taiwandiao

Stock intake. The noise is more noticeable during idle.