my car is not running as it should

[timucin]

turbo drops to 6 psi at 5000rpm.normally 14 psi.it happened suddenly.there is no problem until 5000 rpm .

-no fault code
-changed n75
-changed bypass valve under n75
-all hoses checked


what can it be?

desperately need help

[A6 AVANT]

From the way you describe it "suddenly happened" I would assume it would be a turbo hose going "pop" I know it can be a pain but I would check all your rubber turbo hoses thoroughly even the one from the airbox. There is a thread on here that tells you how to test the hoses under pressure.
HTH
Regards
Chris

[timucin]

would be pleased if you can remember that posts name?!?!
thnx

[S2central.net]

Air leaks are the bain of these cars. You need to remove all the hoses and check them visually internally and externally. If you have access to a high pressure air line and good compressor you can rig up a test kit that forces air into the system at the MAF hose. You need to blank off the breather hose, the hose going to the WG actuator and the hose going into the pressure pipe above the exhaust manifold if you really want to load air thru your plumbing and intercooler. Another possible leak is the hoses at the throttle body and ISV. Need removed for proper investigation...


Paul