Bung Turbo Or Gasket?

[GTR_NUTZ]

Hey all,

I have an R32 GTR, with a few mods here and there. But the other week I’ve noticed a real weird noise coming from my turbos. At first I didn't think much of it, but now it’s a lot louder. I had the engine rebuilt about 4 years ago and new turbos thrown on it, the engine is practically bullet-proof. The turbos are the Garret 2860R like I said they have been on for about 4 years and only done 25-30,000K. Pods are almost new. I have metal plumbing and I know that’s rock solid.

This noise only happens when coming onto boost and during boost, but goes a little quieter when I ease off the accelerator to change gears. BOV's work fine too and the noise doesn't seem to affect the power either.

The noise is kind of hard to describe.. Imagine the normal turbo air sucking noise through the air pods. And then imagine a slight deep metallic rattle inside that sucking noise. If you can imagine that, then that’s what I have.

I have done a little look-see on here and some people have suggested smashed air pods, bung turbo bearings, leaking intake piping, head and exhaust/turbo gaskets. I plan on pulling the intake side of thing apart Friday to have a look at the compressor wheels.

BUT before I do that, what else should I be looking at? AND what are the signs of a leaking exhaust/turbo gasket?

All help would be appreciated,

Cheers,

JUSTIN.

[mad082]

if it is the gasket it will usually be sort of a rattle sound (imagine hitting a metal gasket on on something really fast). it will usually happen when on boost as that is when the pressure is trying to push out and so opens up any gaps and allows the gasket to vibrate.

if it is a gasket it could be coming from a few places. it could be the intake manifold, but more likely either the exhaust manifold, between exhaust manifold and turbo or between turbo and dump pipe. it is rather common to get borken manifold studs on the exhaust manifold so that is where i would be looking first. however you will usually notice a slight change in exhaust noise (depending on what stud is broken, etc). when the car is cold pop the bonnet and look at all the manifold studs (i say when it is cold because you may not be able to see them all and may need to feel under the turbo for 1 or 2 of them. also look for signs of carbon where it may have been leaking.