Ladies and gents,
I'm looking for some advice on a boost issue and this seems a good place to ask!
I've got a 2003 AMK engined S3 with a lovely stage 2 map and in 18 months ownership it's been an awesome machine. Just recently the car has developed a boost problem and I'm not sure where to start in diagnosing it - I'm familiar with Land Rover turbos but S3s seem to be a little more technical!
Basically, the car runs perfectly trundling round at low revs but as soon as you put it under load and get the turbo spinning, then the engine becomes really lumpy, hesitant and gutless. It seems to be burning a lot more fuel that normal so I'd guess it's dumping fuel into the cylinders whilst this is all going on.
Also, normally the turbo gives a nice deep whooosh noise but now when boosting it literally sounds like someone has turned the air conditioning fans on high, with a fan noise coming from behind the dash - it's really weird! When revving the car at standstill I can hear the turbo whistling, so I'm pretty sure it's spooling up alright.
Anyone got any ideas?
I'm thinking a big ass boost leak somewhere but have no idea how to diagnose. Incidentally the brake pedal is also really soft, don't know if this might be related?
Any help/guidance much appreciated!