AdamP

I was driving along on the highway and I noticed that the car had a bit of trouble revving past 4rpm. It would do it but it definately didn't power through like it used to. Next, about 10 minutes later on the freeway I noticed that the turbo would not spool at all. I come to check it today and I noticed that the wastegate actuator came detached (how the hell does that happen anyway??). I popped it back on and the car has not been running the same since.


At any RPM over idle there is a whistle coming from the turbo area. The whistle gets progressively worse as the turbo spools. The sound has a similar sound signature to an HKS SSQV (but CONTINOUS and VERY audible and significant boost...). I had a custom FMIC kit fitted on my ride two days ago and it seemed to be doing just fine before. I checked all of the couplers and they are fine (brand new 4-ply couplers and t-bolt clamps). I can say with confidence that the noise is coming from the turbo area.


I don't know if it would be a busted gasket on the turbo or exhaust manifold. It seems that the turbo is spooling (therefore I'm kind of questioning whether the block->exhaust manifold gasket would be shot... if it were, it wouldn't spool in general, correct?).

The exhaust doesn't seem to be leaking out from the block when I put my hand there and it doesn't sound out of the ordinary. It sounds smooth, not growly or anything.
Would a leak on the exhaust side of the turbo make such a noise?

I'm wondering if there is some sort of weird leak in the wastegate actuator that would do this. It took a little bit of forcing to get some vicegrips in there to force the rod back onto the wastegate? Could I have damaged this? The only other bit I took off was the upward flange from the hotpipe but I replaced it with a gasket again and tightened it down well.

Could the turbo be on the end of it's life? It is just the stock T25g.

My main idea is that since the turbo is spooling it is probably a leak on the compressor side but I'm not sure. That would explain why the car appears to be sluggish at higher RPMs.
I'd also like to add that the gaskets were all changed in Japan with new ones 6 months ago. I was only running 8psi of boost as well.

Wei240

i'd check the ex manifold to turbo gasket, the gasket between the turbo and the elbow, those should be it, but i'd check the gasket from the elbow to downpipe as well...

as far as the actuator popping off, there's this c-clip that stops from it coming loose, that probably fell out, you can stick anything through that hole, it should prevent it from coming loose, heck, you can put a paper clip there if you wanted to...

harleys

i had the same problem quite a while back. found out that the bolts that hold the turbo to the manifold were loose, so air was leaking.

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-harley

Z U L8R

hit the nail on the head, besides that the only other thing i can think it could be would be the actuator itself, maybe the diaphram ripped/tore when the rod shot out and the boost from the hose going to it is leaking out of it, kind of like taking a blade of grass inbetween your fingers, blowing through it, and it making a whistling noise. shouldn't be hard to find a friend with a blown t25 who'll sell u their actuator. you can get the clips to hold the actuator arm on the flap at pep boys in the HELP section they sell a box of various sizes. good luck, keep us posted
Dave

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RB25 280z GT30/76R 441hp/381tq [email protected]

vboy720

Fixed that whistling problem a week ago. I just tightened the 4 bolts after the header/turbo manifold. If ur car is lowered, and you have an exhaust that periodically scrapes, you'll have to tighten those bolts maybe once a week or so. What happens on my car is when the exhaust scrapes, it pulls on those bolts making them loose. If your lucky, your gasket hasnt cracked or broken yet, and you can just tighten the bolts.

FusionR240sx

just searched for this info...
sounds like it could be mee...
gona try it out 2morrow.

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