2005 BEW TDI: P0299 Code

Hey guys, I'm looking for some help with dianosing the problem with my TDI.

So, my 2005 BEW TDI has been low on power for a couple of months. Low enough power to not be able to maintain speed when going up hills. The bad turbo actuator was causing an "Underboost" code, with a handful of others relating to the same issue. The turbo was also leaking oil, so I replaced it with a used one in good condition.

After the install, the turbo was spooling up great and I could actually hear it now. All codes were gone, except for a "Engine Coolant Temp Sensor: Signal Too High" (P0118). And, when I would get into boost past 2000rpm, the car would stumble, and studder.

It is now back to the way it was before I got the turbo installed. But now, with a P0299 code, "Boost Pressure Regulation: Control Range Not Reached"

Could this be a vacuum leak?
Could the bad coolant temp sensor be contributing to the low power? (I've heard of them causing misfires)

Any help would be greatly appreciated.

Thanks in advance!

Ryan

dasrudy said:

It is now back to the way it was before I got the turbo installed. But now, with a P0299 code, "Boost Pressure Regulation: Control Range Not Reached"
Could this be a vacuum leak?
Could the bad coolant temp sensor be contributing to the low power? (I've heard of them causing misfires)
Any help would be greatly appreciated.
Thanks in advance!
Ryan

Click to expand...

Remove your n75 valves and make sure it's not clogged with rust from the actuator. Then check the one way check valve near the n75. It's black and white. Pay attention to which way it hooks up! It's probably no good and full of rust. Then check the vacuum ball on the front of the engine, could also be full of rust. But the n75 is most likely your problem.