Turbo issues

[negativentropy]

My turbo is making a hissing noise, like air coming out of a compressor. This occurs when working hard up hills or accelerating (ie when the turbo is making lots of boost). So im guessing there is a leak somewhere downwind of the compressor. The noise sometimes also sounds like it could be bad bearings.

How involved/advisable is it to take the turbo off, disassemble and inspect it?

[nxski]

Sounds like the pop-off valve is working properly.

[negativentropy]

pop-off valve?

Anyway, this is a new sound, started happening a few weeks ago, doesnt sound right.

[negativentropy]

Hmm on further reading Ive learned what a pop-off valve is and what it does. If thats the source of the noise then I still think something is wrong. Its opening to easily on hills Ive never had a problem on before.

Also there isnt any ball type bearings in this turbo, so that cant be it either.

[Firesong]

Might be a faulty pop off valve.
That can happen.
Less turbo power too

[fredt]

or the actuator arm sticking?

[negativentropy]

Well I took the air intake hose off the turbo and had a look at the compressor - from what I could tell everything was fine in there. There was no play in either direction, thrust or radial. The compressor free spins for about a second if I spin it by hand.

How would I find/test a faulty blow off valve?

[negativentropy]

Problem resolved. It was a seized waste gate valve. The noise was the back up blow off valve. Some Deep Creep on the waste gate valve, push and pull on the actuator and the valve was freed.

http://www.mdocuk.co.uk/forums/viewtopic.php?t=4485

[Firesong]

Excellent!

[del400]

don't know how real these are but...

http://www.ebay.com/itm/Mitsubishi-TD04 ... e2&vxp=mtr