Turbo issue - lack of low boost

[996jimbo]

I know there are previous threads about turbo's but I can't find exactly the answer hence my new one (sorry).

Car is a 2001 130 TDi Sport. I've lost the low rpm boost with boost now coming in around the 2250 rev mark. I plugged it in last night but there were no fault codes. No funny noises from the engine and mpg unaffected (cruising hundred miles today at 70mph getting ave 53mpg).

Turbo has always had a whistle which seems much reduced - the whistle was pronounced at low speed. I am assuming it's the turbo vanes not enabling the turbo to spool up at low revs - would I be correct but should this not produce a fault code? If it is this what sort of costs am I looking at as I'm thinking I could just live with it for motorway driving which is mostly what I do?

Thanks.

[caldirun]

I know there are previous threads about turbo's but I can't find exactly the answer hence my new one (sorry).

Car is a 2001 130 TDi Sport. I've lost the low rpm boost with boost now coming in around the 2250 rev mark. I plugged it in last night but there were no fault codes. No funny noises from the engine and mpg unaffected (cruising hundred miles today at 70mph getting ave 53mpg).

Turbo has always had a whistle which seems much reduced - the whistle was pronounced at low speed. I am assuming it's the turbo vanes not enabling the turbo to spool up at low revs - would I be correct but should this not produce a fault code? If it is this what sort of costs am I looking at as I'm thinking I could just live with it for motorway driving which is mostly what I do?

Thanks.

If the whistle has gone it could be 2 things, the leak has got bigger or your diagnosis is correct, check for leaks/clean vanes. I had the turbo hose blow off the pipe going across the front of the bulkhead, it smoked like crazy and sounded terrible but no fault code!

[martin1810]

Turbo vanes start at max boost angle and reduce as revs rise. Sounds like actuator may not be pulling over enough. This is usually a vacuum leak. If you have vag-com you could log turbo boost pressure from idle to 3000 rpm and see what it looks like.

[996jimbo]

Thanks - will check for leaks before doing anything drastic. Whereabouts should I be looking? Or is that a stupid question and just follow the pipes?!