Turbo Squealing

[sigsputnik]

Hi all,

Well my '94 GTR has started making a squealing noise on boost. Autotech say it could be a dying turbo (they were servicing it at the time).

The guy I bought it from had recently had the turbos 'overhauled' (I have the receipt) with steel wheels. But then the guy at Autotech says they're HKS units (which would make sense - the car has HKS piping and actuators). Some others on this forum have noted that HKS turbos squeal but I have no idea if this is true or not. The car also has a Greddy oil management system. It sucks because I'm pretty good at looking after it.

Any advice on what to do?

Sig.

[Bullet32]

My stock turbo started making a squealing noise on boost and when I took it off to replace it there were small chunks missing from the compressor fan fins.

Im pretty sure that if youre getting a loud squeal it does mean that the turbo is on its way out... Not sure about HKS ones though.

[BNR32t]

My HKS, 2530's dont squeal.

i would call joe at skyline performance.

www.gtr.net.au

My engine was just built by them and i am more than happy with the job.

[StinkyPoo]

+ 1 vote for either bent fins or bearings collapsing.

[SkyGTRline]

Leaking exhaust manifold.

its either the manifold its self or where the turbo bolts onto the manifold..

Check to see if all Manifold studs are there, esspecially on the rear.

And look to see if there is any carbon around the manifold..

had Same prob, common thing sposably..

[Scooby]

turbos don't squeal unless they're really happy and they're girl turbos.

seriously; have a look at the turbos with a torch, it will either say Garrett or HKS on the inlet side but neither should squeal. who did the overhaul?

does it come and go with revs in neutral, revs with little / no boost or revs with load / boost. exhaust leak should make a ticking noise.

if it's easy to make it happen listen under the bonnet so you can try and pinpont the location of the noise. hopefully they can be more precise than 'could be a dying turbo' as you're unlikely to want to take the the turbos off on that basis.

cheers

[StinkyPoo]

Is is more like squeal like a whistle or a squeal like a zing?

A leaking turbo gasket i fixed was making a whistling sound.

I guess it's hard to tell without looking at it first hand.

[sl33py]

My guess is the turbo is dying. Mine squealed/made a whizzing sound when it died. Did it in neutral too.

[sigsputnik]

thanks heaps for all the great suggestions guys - it sounds more like a whistle than a zing. Like when people watch fireworks. Oooooh! Pitch gets higher as you accelerate. I think it only really starts at about 2100 rpm.

i do hear a ticking sound at idle, with the bonnet up.

i'll have another look at it in daylight tomorrow.

[GeeTR]

If they're newish HKS's or overhauled, then I doubt the comp wheels rubbing on the front cover.

Considering they were recently taken off the car, i would say that its an exhaust leak, did you (or they) use the old gaskets?? Ill put 100 internet dollars on it.

[R33Gtst Driver]

If they're newish HKS's or overhauled, then I doubt the comp wheels rubbing on the front cover.

Considering they were recently taken off the car, i would say that its an exhaust leak, did you (or they) use the old gaskets?? Ill put 100 internet dollars on it.

100 internet dollars lol nice

please do tell us what the problem ends up being i have a problem car so when it happens to me id like to know what it is.

[sigsputnik]

hi guys,

ok, i think i can see one of the turbos (one side, at least) at it says "Garrett" on it. Can't see anything saying HKS, but the guy at Autotech was pretty convinced, though?

The workshop was Precision Turbochargers. 2x Turbo's overhaul, 2x steel wheels fitted, $1600.

The 'ticking' i can hear in the engine bay is actually more of a tapping, on the left side of the head, rather than the turbo side. The tapping seems to stop momentarily when i rev it.

christ i wish i knew what i was doing.

[SN33KY_SN33KY]

how loud is the ticking??? if its not too loud id dare say its just ur injectors its not a problem

[Scooby]

RB26s have noisy top ends, the inj and solid lifters see to that.

HKS turbos have HKS in raised lettering on the intake ie silver housing on the side facing the front of the car. if they were HKS turbos and were 'steel wheeled' that's unusual as they have steel wheels anyway, unless they were damaged. if the housing says garret it sounds like maybe they've just done a steel wheel coversion on the stockers.

did autotech suggest anything other than a turbo? i'd hope they could be more specific, or are they just as confused? try taking it to Trojan, John is a cluey guy.

don't worry too much, engines have all sorts of weird ass ways to make noises. have a look at your accessories, the ps pump can make bad noises when low on oil, and the a/c comp sounds like a meat grinder if it needs gas or it's bearings are shot.

also engine fan clutches make strange noises when they let go, alternatively see if the fan is hitting anything when it turns.

[race_snooze]

oh... my 25/30 kind of does and its almost brand new, but its more a whine than anything, a sequel is either exhaust manifold crack or leak, if it is the turbo then well not so good, take it to trojan for a second look!!!

[Frink]

Leaking exhaust manifold.

its either the manifold its self or where the turbo bolts onto the manifold..

Check to see if all Manifold studs are there, esspecially on the rear.

And look to see if there is any carbon around the manifold..

had Same prob, common thing sposably..

agreed... if the turbos are still performing well and not dropping much boost, then i'd say this is your problem. happened to me as well.

[sigsputnik]

hi guys,

i haven't yet taken her in to be looked at (work issues). but i'm coming round to the idea of a leak.

when i dropped it off, my two complaints were that:

since they'd tuned my new powerfc, the car had been running very rich (400 kms per tank, whether i floor it or drive like a granny - 520kms per tank with my old mines computer). he said the original tune had been fine, something else must be doing it.

second, at idle, she frequently 'hunts' (revs by itself).

so i guess it could be a leak somewhere?

[Frink]

sounds like your BOV might be giving you some strife. its a common problem, nothing to be too worried about. i dont know the reasons behind it happening, but it does happen. Bullet32 will know the answer... (he saved my baby!)

[JD-33]

The 'ticking' i can hear in the engine bay is actually more of a tapping, on the left side of the head, rather than the turbo side. The tapping seems to stop momentarily when i rev it.

tapping noise would be ur tappets. http://en.wikipedia.org/wiki/Tappet

[TailsTails]

tapping more likely to be injectors