High Pitched Squeal On High Rpm / Boost

[Everlong-S13]

Hi guys, I know this has been discussed in a few thread before, I'd just like some help identifying something.

Occassionally I get a high pitched squeal or whine from somewhere under the bonnet, hardly happens, I found downshifting into third or second and giving the car a bit of juice in high rev (3500 - 4000 rpm) and full boost makes the noise last for a second or so.

It's quite hard to replicate. Anyway from a few threads I have read people are recommending checking the turbo exhaust manifold etc for loose bolts and such.

I've taken off the turbo heat shield and not sure what to check. Most of the bolts were pretty tight already, I did notice that there was a bolt missing on the manifold and I'm not sure if there was an existing bolt there or not? Anyway I half screwed in a bolt in there to see, took the car for a spin, couldn't get the car to re-create the noise however I didn't notice a small chirp in second gear that may have been it starting.

Anyway, see the pic below. Is there anything in the pic I need to check, and should there be a bolt in the spot I marked?

[ARTZ]

that bolt is nothing...it just holds the heat shield on

when mine started squealing it was the bolts that hold the turbo to the manifold (the one you can see in your picture actually as well as another one)...I tightened it with my hand and it was good again for a bit...

just feel around the turbo and manifold bolts to see if any are loose...

[Everlong-S13]

Thanks mate, classic noob stuff right there. Took the heat shield off so fast forgot where the bolt that held it on was.

I will have a closer look at the bolts you were saying however most of the bolts I checked were already tight.

[GTSBoy]

4 bolts on the turbo flange. The ones underneath are a bit harder to reach. These are the usual suspects. It doesn't matter if they are tight, if the gasket is damaged.

[Manuel Kasko]

Got the same thing

Guessing I need a new gasket as well.

Did what you did and tightened the bolts it didn't fix anything. Let me know how you go

[AngryRB]

when i had that noise it wasnt the exhaust but the intake manifold gasket. sounded like a strangled cat under the bonnet.

[Everlong-S13]

I'll let you know guys, I'm not going any further than tightening bolts, cars going into a place for a tune next week so hopefully they can find the problem, and it doesn't stop them from being able to install a Nistune.

[SCR48]

Mine did this a while back, ended up being a intake gasket..

[34GeeTeeTee]

Had a mates car do that and it was a tiny split in a cooler hose (was the elbow under the turbo from

Memory) it would only do it under full boost and the split was really hard to find.... Long shot but I you don't find the other issues then it's worth a look

[gaidzin]

Mine did this a while back, ended up being a intake gasket..

sorry, was that the gasket between intake manifold and the engine head or the gasket between the parts of the manifold itself? pardon my English, I'm from Russia))

[Manuel Kasko]

Mine ended up being between the parts of the intake manifold.

Not the one from the head

[GTSBoy]

sorry, was that the gasket between intake manifold and the engine head or the gasket between the parts of the manifold itself? pardon my English, I'm from Russia))

I wouldn't worry. Your English appears to be better than most Australian forum posters'.

[wolverine]

I wouldn't worry. Your English appears to be better than most Australian forum posters'.

Yes.

[Room42]

Squealing is from tight or loose belts African Americanachi. Have a good feel of your visible belts. Maybe lay of the maccas. It could be your wife complaining. Mine does. Its a high pitched squeal the whole way there until her fat cake hole get filled. Nah kidding, she is a beautiful 5"10' 26 yro bitch! Or loosen your cam belt. But dont do that cos you dont know what the f**k you are doing.

[Manuel Kasko]

Nathan that makes no sense

[Tai1or Made]

Lol.

[WARLORD]

same problem for a while things ive checked on inlet side cos that's where its coming from.the noise starts at about 7psi

manifold gasket.

disconnected factory boost gauge sender.

checked intercooler joiners for pin holes.

checked hoses for splits as this has happen be for to me.

even had a smoke test twice.

the only thing left for me is the pvc valve and hoses to the pvc

its a split hose some where i think cos it needs some psi be for forced open and whistle

[Dose Pipe Sutututu]

Squealing is from tight or loose belts African Americanachi. Have a good feel of your visible belts. Maybe lay of the maccas. It could be your wife complaining. Mine does. Its a high pitched squeal the whole way there until her fat cake hole get filled. Nah kidding, she is a beautiful 5"10' 26 yro bitch! Or loosen your cam belt. But dont do that cos you dont know what the f**k you are doing.

epic post +1 Like

[newboost]

I had pretty much the same problem as you have. I had checked all the gaskets and still could not find the leak. It was also happening at 7psi and above. I had replaced all my vac hoses & all new clamps. Finnally I made this up and found the leak in about 5 mins.

Remove your intake from the front of the turbo, Attach the hose with valve to the front of the turbo, pump up using compressor. (no more than 10 psi) You should be able to hear the leak.

(Engine off, It will not hold pressure long. Just enough to find the leak)

Parts used to make this are

1 right angled silicone pipe from old stock intercooler pipes (or from any auto store)

1 screw in tyre valve

2 hose clamps

1 plastic pvc end cap (bought from a plumbimg store)

Edited October 8, 2012 by newboost

[Room42]

Sorry guys I must have had a big night when I posted that.