breakfast

iTrader: (4)

I've got an interesting noise coming from the engine bay, the best way I can describe it would be: sounds like a field full of crickets in the engine bay, and it varies with engine rpm. There's a higher pitched 'whistle' too, but I don't think that's anything (correct me if I'm wrong). It's the 'field of crickets' I'm after.
I can't pin down where its coming from, but it sounds like the front/top of the motor itself. Maybe more prominent on the turbo side? It almost sounds like a belt to me, but I just don't know. I'm looking for second opinions before I go taking things apart, on the off chance anyone has experienced this.

I've been hearing it for a while now, but it seems to have gotten slightly louder? Maybe I just care more because I've dealt with some of the more pressing issues. I notice it most driving past buildings or guardrails where the sound comes back at me from one side or the other. I really wouldn't notice it if it wasn't so damn loud..

The car is very modified:
- emissions equip. removed
- ac + heater removed
- aftermarket IC, rad, intake, tubing
- 850 primaries, 1300 sec, twin power, power FC
- downpipe w/ no cat, 3" resonated pipe back to muffler
- simplified sequential w/ stock twins
- probably something else important I'm forgetting

adam c

iTrader: (2)

My guess is that the alternator bearings may be bad. Remove the belt and start the car. See if the noise goes away.

SidewaysS30z

Exact same thing I would suggest trying. This will immediately tell you within minutes if the noise is related to anything powered by the belt. super fast / easy check.

armans

iTrader: (2)

A chirping sound? If not a belt, might be the clutch release cylinder going bad or already so. Keep an eye on the brake fluid level, see if it is not gradually being lost.

7krayziboi

iTrader: (15)

My guess , aftermarket flywheel

silverTRD

iTrader: (37)

Oh that would drive me nuts. Get one of the stethoscopes with a metal stick end on it from harbor freight and start touching it to everything with a moving part on the engine. Helps to troubleshoot bearing issues for me.