Boost Issue

[Jhols1]

Long story short, exhaust manifold stud was stripped out, so pulled turbo and manifold off, install helicoil, re-install manifold and turbo. I also removed the cat.

It usually hits full boost at 4000rpm, but now it has no boost until like 6000rpm and even then it's only a couple pounds at most.

Car is 32 gtr rb26 t04z turbo.

As far as I can tell every bolt and hose clamp I undid I have done back up tight as it was.

Thinking computer issue or waste gate issue???

Turbo spins fine and freely as it should.

[Ben C34]

The chances of the computer causing the problem straight after you did work is unbelievably low.

Boost leak is likely.

[admS15]

Wastegate stuck open or turbo died.

[GTRPSI]

Most likely waste gate stuck open or partially open.

Also check your boost side hosing and clamps.

[SkudR33]

I hate when this happens! You go about fixing an issue and you fix it perfectly... Nek minnit unexpected problem arises and ruins it all for you. I'd put my money on an air leak aswell! Good luck with it...

[statue]

Similar thing happened to me 2 weeks ago.

• Boost suddenly slow. Full boost at 4500 rpm instead of 3600 rpm
• Manifold stud went missing
• Turbo spins fine
• Hardly any shaft play
• Compressor wheel looks fine

Mine however, made a noise. When the turbo was removed, the turbine wheel was checked - a fin was chipped and another is cracked

Hopefully its not the same issue.

Since yours isnt making a noise (is it?) and also a big jump from 4000 to 6000 then I'd also say its your gate being partially open.

Good luck

Edited November 7, 2015 by statue

[Jhols1]

Stared the car up and my screamer pipe is getting hot, so I've undone the clamp on my external waste gate and had a look and it appears to not be closing properly.

It is a turbo smart 50mm

[Ben C34]

If it's a screamer surely you could instantly hear if it's leaking.

[Jhols1]

Found the problem, the seating ring/flange fell out of the waste gate while it was all apart, so the gate couldn't close properly.

Found the ring and put it back in, and it's all fixed now and business as usual