I Dont Like The Sound Of This...

[rednut]

Hoping someone can put my mind at ease and give me an idea of what this awful sound might be... :boohoo:

If i driving along and rev the car with anything more than half throttle over 3.5k/4k rpm, a real loud, mechanical type noise comes from under the bonnet. It almost sounds like a whistle being blown into really, really, really hard - like by compressed air or something. Now if the car is idle and i floor it and rev over 4k rpm, this sound does not occur.

I initially thought it was my turbo, so i had a cry, started cursing randomly, kicking things and abusing random passers by from my balcony. I then composed myself and thought about it and went for a drive. In 4th at 100km/h, i floor it and sure enough, full boost comes on and i'm away - but no sound (not that i could hear anyway). So i was a but confused after this...for reference, below i have listed previous issues by car has had and current mods

Previous Issues:

1 - my power steering belt just came off one night under normal driving. They have 3 "ribs" and one of them just sheared off!

2 - on a HOT (track temps 50 deg +) track day at Eastern Creek my power steering fluid shat itself all over my engine bay, refilled it and all seemed well

Mods:

Apexi PowerFC

3" cat back exhaust

Pod type ir filter

Bleed type Boost Controller (boost now up to 11-12psi)

My bro reckons it could be my injectors but after writing this and seeing the 2 issues with the power steering - maybe its that...anyone?

[GTRgeoff]

Just a starter, try checking the gaskets on the exhaust and inlet. Do this cold with the car running and use a spray bottle to get the water onto the intake and exhaust manifold joins on the head and the turbo mount. If you have bubbles it's a leak. if not that's one less cause.

[Timd]

my rb20 was making the same whistling sound. It was an exhaust gasket. Would only happen at certain revs, very annoying. the gasses play the gasket like a reid .DOnt know which gasket it was as there were a few gone. Check them like Geoff said. It should be pretty obvious if its leaking that bad