View Full Version : Turbo Underboost P0299 K30-53039700106 replacement?

10-23-2018, 11:12 AM
First Audi for me and I am working my way through the bugs. So far I have changed out the DV, PVC and Thermostat. Car idles smooth and runs great if I keep it below 2500rpm. If I push it, the check engine light would come on with a P0299 Turbo Under boost code. With 123k miles on the car, I am seriously thinking of replacing the turbo assy with a rebuilt unit. I have done quite of bit of research and from what I have read the K03-29 would be a good target. How ever, I am not sure what is the proper replacement for the K30-53039700106 stock turbo unless its another K30-53039700106 rebuild. Not looking for performance other that a solid long term and reliable replacement. I also understand there are some turbo releases to stay away from. The existing part number was retrieved using a 4ft long fiber optic inspection camera. The last 3 numbers were a guess as they sit behind a bracket that holds the N75 valve.90172
From what I have seen the cost for a rebuild can go anywhere from $274 to $600. The warranty goes according to the price ranging from 1 year to 3 years at the high end. Does anyone have a good source without breaking the bank? There is a semi-local re-builder here that sells the exact model rebuild for $325 or so. I also do not know how to correlate the K03-29 to part numbers that would be a correct direct replacement.
Thank you in advance for the assistance.

10-23-2018, 02:07 PM
- So this is a 2000 or is it a 2001?
- Does it run well over 2500, just throws a code?

Things I would check:
- fuel trims in block 032
- Boost log on a 3rd gear pull after a fresh code clear
- Output test of N75. Make sure she clicks nice.

I'm not sure what number that turbo is, but there are only 2 stock turbos for North American A4 1.8T's: K03-005 for the AEB cars (97-99.5) and the K03-029 from the 2000-2005 cars. The 029 is the better unit and is a direct swap for any A4 1.8T. That said, 128k miles is not too many for a turbo to handle. It's possible the turbo is fine and you have a different problem. N75 (wastegate control device), wastegate actuator, boost leak, faulty sensor, etc.

10-24-2018, 05:17 AM
I must apologize, I just realized that this is the incorrect forum. Should of been B7 A4. The car is a 2007 A4 B7 2.0T. I think that I should close this thread out and repost to the correct forum. Again my apologies to the list.
Thank you for your response. To answer one question, yes it runs fine even with the code.