Turbo Noise (1 Viewer)

[Rakaposhi]

While doing some pump tuning runs, the following noise started:

Turbo Noise

The vehicle is still drivable but anything above 2psi boost, the noise becomes high. It sounds like a siren.

Vehicle Details:
1996 HDJ81 with 1HDFT and auto trans. 3" exhaust.
Stock CT26 with Front Mount Intercooler and MBC set to 14 psi.

 

[mudgudgeon]

Is it the original turbo?

Have you taken the intake hose off and inspected the turbo?

You want to look for shaft play. The compressor wheel should not move in/out. And side to side should only have a tiny bit of movement. Barely visible. You'll feel slight movement, but not much at all.
There's specs and instructions for a proper inspection in the engine workshop manual.

Check no blades have cracked off.

If there's any sign the blades have, or could touch the housing, time to rebuild or replace the turbo.

Do not drive it into you have inspected the turbo.


It might be a boost pressure leak from a hose, or bad rubber gasket on the intake manifold etc

The fact you hear the noise as the turbo just starts to spool up says its a turbo issue, not a boost leak.

 

[mudgudgeon]

If you haven't already found it, go look through the diesel tech section of the forum. You'll find a lot of info relevant to your engine.

Engine repair manuals are in the RESOURCES section found in the forum menu

 

[Rakaposhi]

The turbo was rebuilt about 10k kms ago.

I did check for the shaft play. There no in-out play. Slight play from side-to-side. Doesn't seem excessive but I didnt measure nor am I an expert. Visually the compressor fins seemed fine and not touching the housing.

This issue happened a couple yrs ago while traveling in the mountains. It was in the middle of nowhere so I kept driving with a very light foot (not building boost). After about 3-4 hours the issue disappeared on its own.

I'll check for boost leaks first before getting the turbo out for inspection.

Thanks.

 

[charlay61]

Wastegate stuck half-open ? Boost leak ?

 

[Rakaposhi]

Wastegate stuck half-open ? Boost leak ?

My first guess was stuck wastegate. I assumed that because when it happened previously, it could have gotten unstuck and fixed itself during driving. Plus I increased the boost just now to 14psi after the intercooler install. But if the wastegate is open then would the turbo still spin like this? With wastegate open, I wouldn't get any boost.

I'll check for boost leak next weekend and narrow it down.

 

[Rakaposhi]

So I checked for boost leaks. Found 4 minor ones. Fixed them.

The noise is still there.

What should be the next step?

 

[Rakaposhi]

Compressor side :