ive got a 2000 1.8T and i have a problem with it. it seems when i hit full boost in say 2-3 gear the boost just stops. its dead. if i shut the car off and turn it right back on the boost is back until it hits full boost again and then it is gone again. i took it to my wrench and checked the codes and nothing was up. he was starting to think that i have a bad N75. what do you guys think? thanks for the help

 

sounds like limp mode.




Are you getting a turbo overboost code? Any codes at all? Posting the codes will save lots of guessing.

 

there are no codes being thrown

 

anyone?

 

Bad N75 maybe? Limp mode could be due to over boost because of the bad N75. Do you have a boost gauge? How many psi of boost are you getting up to when you car shuts down?

 

i dont have a boost gauge but when my wrench and i were lookin at it i was out drivin with the VAG on it and i dont remember how much boost it was stopping at.

 

Sounds like you're overboosting. Check for codes.

 

the car isnt overboosting, and there arent any codes. i dont think that it is in limp mode because i did some boost logging and the requested amount of boost was what it should be and the actual amount of boost was way low

 

Well you kind of answered your own question.

The system is requesting the boost, but actually no getting it, so you have a boost leak, or malfunctioning part, probably a bad n75 as your mechanic suggested, or or bad DV.

If you know someone else with the same car, you can try swaping the parts out and see if either of those fix the problem.

 

i went in and replaced the n75, and still a no go, and the DV is fine. anyone else have any ideas?