[Tinfoilzhat]

HELP !!!!

I have the dreaded drivetrain120308 pressure too low issue. It triggers when I get heavy on the pedal 100% of the time. if I reset it after it triggers and before shutting the car down, it does not come back. It will come back 100% of the time after a restart + heavy pedal. Performance after the reset is Ok but does not really feel like what others describe as some hard torque pull. Bimmer link is reporting what looks like max boost in the upper 14 PSI which seems too low (i'm not sure what reading to reference - Boost pressure PSI, Boost pressure setpoint psi or Boost pressure raw value psi) Overall, power feels off.
Im new to this X3 (just bought it) and its a well maintained 2013 - just up their in the mileage.

Observations to date:

- Waste gate does not look to have any play ( I removed the actuator also to see how the gate felt - seems OK).
- Smoke test not surfacing any leaks
- Replaced the Pressure regulator - no changes
- Slight oil in the pressure reservoir - not a puddle or even a drip
- Air pump is original but I do see the Pneumatic waste gate controller operating full range.
- Pneumatic waste gate, lines and reservoir all hold hold pressure
- Replaced gas cap - no change

I did buy a replacement air pump but did not replace it yet (Holy tight ass space!!). Oddly, when I bench pressure test it, It runs to 30 PSI and then falls. The one on the car does not hold any pressure at all but I can clearly see its actuating the vacuum wastegate controller.

No other codes beside vtg oil wear.

I have bimmerlink and a scan tool for BMW so I can read and report on values.
What else should I be checking or replacing ? Relieve valve?

[andreigbs]

The one on the car does not hold any pressure at all but I can clearly see its actuating the vacuum wastegate controller

Is it possible that the controller will still move the valve closed/open whether or not the pump actually holds pressure? I would swap with the new one, since you have it available, then you can rule it out if nothing changes.