Overboosting V6 tdi........HELP!!!!

[nice-one-bruv]

Does anybody have any ideas for my 2002 2.5 v6 tdi quattro sport? It seems to have an overboosting problem, it fact 'seems' is a little understatement as when it was on diagnostic computer last week the boost pressure peaked at 36psi!!!!!
The car starts and drives fine, boost is all good until you reach 2250-2500rpm, and then the turbo reacts as if youve released the throttle, dumping all the boost, presumably through the wastgate.....
In 4th, 5th and 6th its as if there is no boost at all

The hoses and vacuum pipes are all good, the diagnostics showed no faults and im running out of ideas and patience. I have changed the thrust sensor on the LH intercooler and the boost valve which carries the vacuum pipe to the actuator and dump valve. I have also changed the RH intercooler which started to leak badly(not sure if this was a result of the overboosting problem or was already there)

Any ideas............???

 

[Broken Byzan]

sadly sounds like sticky VNT mechanism.

If the actuator is working correctly, then it will be the turbo vanes sticking. You could try cleaning them using the innotec turbo cleaning chemicals or replace the turbo


edit, you could try this, nowt to lose.

http://www.audi-sport.net/vb/a4-a4-...sis/129531-wow-mr-muscle-turbo-cleanning.html

 

[nice-one-bruv]

Im going to be checking the actuator tomorrow, just for leaks and stuff.
Do you know of anyone that has used the Innotec cleaner and what results theyve had. Someone else mentioned a cleaning product earlier today but not sure what it was called, it may be the same one.
Forgot to mention that during August the car was not used on the road, only started and moved out of workshop, and then again back into workshop at end of day, thus now realising that carbon build up could have been increased without the turbo being able to 'shove' it out the back. Probably dont help that the car has done 182k either............this could get expensive

 

[swarcup]

use the mr muscle cleaning on the turbo and you will see a difference £3, have a read of this if you want inspiration Chemical cleaning for turbo vs removal? - Page 6 - TDIClub Forums i looked at the inotec stuff but opted not to use this after talking to people who had tryed it to no avail. the mr muscle seems to be the one, i used it on my 2.5 v6 this weekend and it has improved the boost deffinately. overboost is useually sticky vanes.