Hi guys i have a subaru impreza uk 2000 1999 model, it was boosting ok earlier but now its not. My dump valve used to make a noise on about 3000rmp now its 4000 rpm and its really quiet. Can anyone help. I have an idea it could be if im right the boost solenoid or the dump valve wants cleaning. Could it be my turbo by anychance.

 

What DV is it??

A bailey per chance??

 

No mate FORGE i only cleaned it last week, it seems to move easy enough just no noise.

 

Did you check the 'small' spring in the top??

You could always remove the forge, block the pipe off and see how she boosts then. This would defo prove the DV either way.

 

My Dv fits onto the intercooler, there is an hole on front of intercooler were it fits, there is one pipe comeing from it to the engine bay, so doin this how do i block the hole or is it ok with the hole there...eg.. will it run ok as i test it.

 

No, you'll need a blanking plate.

 

Yeah, as above mate. Not hard to fabricate yourself, or a temp job just to test. Other than that, can you borrow another DV?

 

Right i took dv off and ran the car without it and it still does it, sometimes it boosts ok then it dosent. If it was my boost solenoid would it show a fault code. Also what does a turbo do when it is said to be lagging if i got that right.

 

I assume you fabricated some thing to blank the i/c and the vacuum hose when you did this??

Not always, no. But if it was it would be a code 45.

You running a 2 or 3 port BCS??

Lag is, in layman's terms, the delay between your foot hitting the carpet and the turbo kicking in.
Usually, the bigger the turbo the more lag. But if mapped correctly it is not an issue.
For example, the TD05 is said to be 'laggy' compered to the TD04.