Originally Posted by sunny
I had this problem, cured half of it.
Finally the turbo blew so I replaced it with a replacment item however soon afterwards the car was flat as a fart. I changed the Airflow Meter and the car turned into the rocket again however only in the lower gears (1,2 and 3) when in 4th, 5th and 6th (longer gears) once planted down it hits a boost limit then goes into a limp mode with very slow response again. Once the car has been turned off and then on again it clears. Then I decided to take the car out with the VAG diagnosis equipment connected to it and when it goes into limp mode it indicates that there is a fault with the boost solinoids (which I have JUST replaced) therefore I am assumming that the small diameter vacuum hoses that are connected to the soliniods and the wastegate etc which look like they've seen better days should be replaced....thats my next mission. Hopefully that sorts it. It will be ok in the higher gears so long as you dont open full throttle, in other words if you feather the throttle / boost in its fine this kind of indicates a leak somewhere when boost builds up?
This is exactly what my 1.9tdi quattro Avante does, VAG diagnostics said AFM, so I changed it, still did it, then I changed the boost solenoid and it still does it. My turbo is always whistling though? Make me think actuator is stuck open, allowing to much boost reulting in ECU switching to limp mode. On the motorway you can't go over 80 as it's under load and over 3000rpm hits the limit again?
Confused. otherwise an awesome car.