Hey. Just got this car- first turbo I have owned so not sure what this noise could be. It's when I slow down, either through gear changes or just pushing the clutch in and braking I get a funny whirrring noise. If you can imagine blowing into a half empty coke bottle softly, it sounds like that. As soon as I accelorate it stops but when I take my foot of and start slowing it makes the noise on and off. Once I stop there is no noise but on idle if I rev it and take my foot off it will do it again... back pressure probz? I have no idea. Any thoughts??? Its a HDT 5 Speed. Cheers!

It could be your throw out bearing in the gearbox. Its easy to replace, but the box will have to come out.

Thrust bearing in the gearbox thats making that noise

Thrust=throw out bearing. Ring Repco, Holden or your work shop and the'll be able to supplie you with a new one. Good luck

Wouldn't the thrust bearing noise only happen when pushing the clutch in and out? This does it on engine retarding at low low speeds.

Before you start doing all of that, have someone listen to your airbox. That "blowing on a Coke bottle" bit just sounds like the standard hooting kind of induction noise they all make, except it gets worse if the little curved intake piece is missing or loose on your air intake box. Should do it on stock VLT's if you rev it and then back off suddenly, either while in motion of standing still. Nothing to worry about.

I think you have hit the nail on the head. The little curvy thing is not there, I'll replace it with CAI for now until I get a cooler. Cheers mate, love these forums haha!

No worries. After seventeen years I've almost got every noise sussed on the old girl.......til the next one crops up.

It's your airbox for sure!! I took the snorkel off mine and opened up the airbox and it whirrs BIGTIME now. It is actually quite annoying!! In fact cutting the airbox open changed the acoustics of the intake remarkably. Also now when I snap the throttle shut under boost the "cooooooooooohhhhh" noise is twice as loud too... I'll put the snorkel back on until I get a pod.

Yea it is VERY annoying haha I hate noises and rattles, they get to me... time to start sussing them out now too.