Hi all. I was driving to football this morning and as i started to boost in 3rd gear all of a sudden my boost cut out and dump valve released all pressure just as if i let off throttle.
No smoke at all and turbo wont go over 0bar of boost. Had a good look under bonnet and cant spot anything obvious.

Im not really a mechanic by any stretch but i know the basics.
Can anyone help we things to check please?

All help appreciated
Thanks

 

Oh and just to add its a v4 sti

 

I had a similar experience recently and it was caused by the turbo bearing failing. If yours is the same thing you'll have to rebuild the turbo or replace it.

 

Its a vf22 and was mapped at a steady 1.1 bar. Hope the bearing hasnt gone but im not sure with what to start checking =/

 

I guess the first thing to check for is any leaks on the inlet side. If you've done that, you might want to manually check the turbo spindle. If you take off the inlet side of the pipework that goes to the turbo, you should be able to see/ feel the impeller. There shouldn't be any significant play in the shaft and it should rotate smoothly. If the bearing has gone, it should be pretty obvious (mine had around 3mm of play and you could feel resistance when turning it).

 

Sounds like dump valve may be past it or the noise you heard was a loose hose or a split hose

 

Mine did this and made horrible noises after too, pipe had came off my intercooler. I forgot to tighten it! Check all pipework before doing anything else.

 

It was intercooler pipework had come loose under the air filter. Thanks for comments and help guys problem fixed.