R34 Gtt Shriek Noise

[Granthem]

Pulled inlet pipe off turbo read below down the page.

Hi guys,

basically the noise its kind of like a quiet external gate with a screamer, but heres the punch... its only noticible (well really auditable) in first gear.

Car is boosting normal, all other vital signs are normal.

I can load it up in 3rd gear full boost and no noise. So im not thinking its the turbo. Im hoping its a gasket, but again i would think it would be consistant.

Either way its loudest in first.

Any ideas? It might be a gasket as its not doing very high revs when testing it in 3rd

then again, its not really noticible in second (although i think i can hear it)

any chances of it being in the gearbox, and only effecting first gear?

I did a search but it seems to be different, as its only really first gear. Which to me points to the box.

Best way to describe is a shriek, or close to an external gate with a screamer (but not that loud thank god)

any feed back would be great car is manual by the way

Edited March 19, 2008 by Granthem

[GeeTR]

Thats wack. All I can think of, is that the tourqe of 1st is creating abnormal engine twist, and exhaust flange separation??? Strange

Do the old "block exhaust at tip" and listen for leaks.

Edited March 4, 2008 by GeeTR

[Granthem]

Yeh. I have just been babying it around recently moving gear to my new house. Now its suddenly making this noise, but to get it to happen i need to really pin it and get it revving

Edited March 4, 2008 by Granthem

[The Mafia]

mine does it - tighten the bolts that hold your turbo on. They'll make the noise as soon as the exhaust pressure gets higher etc.

[GeeTR]

Surly I'm thinking Mafia's on the sulphuric money, but why 1st gear i still think? Theres no real load, creating no real boost to = the squeal + (real boost pressure)

Stranger still...

[Granthem]

Surly I'm thinking Mafia's on the sulphuric money, but why 1st gear i still think? Theres no real load, creating no real boost to = the squeal + (real boost pressure)

Stranger still...

thats exactly my thoughts aswell, its only there in first. But its definitely there. when next to another car its nearly like a screamer lol

then second its gone (i think - no where near to the same level anyway)

thanks for the thoughts guys ill check over for some leaks

[GTR-32U]

sounds like the turbo to me...happens in First gear because the turbo has to spool rapidly might be a bit of play in the turbo

[Granthem]

Could be... but surely it would still make the same noise when holding max boost in each gear still?

[R338OY]

Maybe the engine is just scared...

[Granthem]

Maybe the engine is just scared...

:laughing-smiley-014:

Of me... never... the drivers we have around our town to contend with though... possibly.

I just cant work out why its there in first and not the others. I really gotta be revving it hard to, like probably from 5500 onwards

[chrishelliwell33]

i had the exact same thing happen in my old S13, was a crack in the manifold, would only do it at high revs, when the engine and turbo were hot as, forcing the crack to widden enough to let air out... check the welds in youe manifold, its a possibility it could be cracked, sounds very similar to the problem i had.

[Granthem]

That sounds interesting... might be a good excuse to a stainless steel one

[GTR-32U]

I had the exact same problem in my 32 when I first got it.it only did the noise in first gear. And if I dropped the boost down from 1 BAR down to .8 then it didnt do it as badly.After a year and a bit The Turbo eventually started getting the old waft of white cloud after sitting at the traffic lights so I had the turbo off and rebuilt along with all new hoses and a new dump pipe while I was at it. Never had the problem again after this.I never realised what sort of gain this all made to spool up.Fantastic!!.Just wish I changed the CAT converter as well...oh well

Edited March 7, 2008 by GTR-32U

[stolen_s15]

i had the exact same thing happen in my old S13, was a crack in the manifold, would only do it at high revs, when the engine and turbo were hot as, forcing the crack to widden enough to let air out... check the welds in youe manifold, its a possibility it could be cracked, sounds very similar to the problem i had.

Thats what I was thinking.

The sound you describe is almost certainly an exhaust leak somewhere near the turbo. Could be a craked manifold or dump pipe, could be loose turbo/dump/mani bolts, or could be a gasket on the edge of death. Check all those things and let us know how you go.

[dano4127]

$10 says its a gasket on the edge of death

[bubba]

My 20 gearbox was shrieking before I pulled it out.. I thought it was maybe the clutch or something but when we put the 25 box, didn't touch the clutch at all and now it's gone.

Could drive normally with no shriek but as soon as I loaded it up EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEK

[Granthem]

Yeh well having all stocko boost lines etc still attached when purchase, and ive only now raised it to 0.7 bar, im hoping the turbo has abit of life left in it. Will start pulling shit apart on the weekend, fingers crossed i find a gasket problem

And the first gear thing makes me think gearbox, however a mate and I listened and its just there in second.

Will pull the turbo off on the weekend and let you guys know what i find!

[Granthem]

Update guys and grrrls. Pulled the front inlet pipe off the turbo last night, oh what a horrible job. Anyway, back to what I found. There are NO (sorry big typo mistake) wear marks at the front of the compressor housing. The turbo is spinning well when turned with just your fingers. Shaft play side to side is very minimal. HOWEVER. there is around .5 - 1mm of play backwards and forwards (as in pushing the wheels towards the dump pipe, pulling back etc). actually there is enough to make a small noise when doing it. So my question is how much play does everyone elses turbos have. Being ball bearing, any play at all is not good right?

Looks like it may be new turbo time. Turbo looks perfect, but its the back and forwards movement thats the worry. So basically how much is acceptable/normal on a ball bearing turbo like mine?

I have read that it will always have some side to side movement when there is no oil in the turbo, but this doesnt affected end to end movement? correct?

basically ive searched and read that end to end play = not good, but im just wondering how much is normal

Edited March 20, 2008 by Granthem

[Granthem]

no-one knows an accepted figure. felt a brand new one today, it had less of course, but still has play. so its hard to say whether mine is normal or too much

[666DAN]

I would have thought the Nylon impeller would have vapourised if it had even looked sideways at the inducer? Definately score marks, not machine marks?