[Carl Morris]

...and today when I drove it I had what felt like no boost (Cobb said ~3psi) and it was throwing codes P2AAF and P30FF. At one point it said something about fuel pump on the display. I tried a different Cobb map, no change. So I uninstalled the Cobb and it immediately threw the codes again and still won't boost. So anyway, at least it reproduces in stock mode, guess I'll call the dealership tomorrow. I hope they can get it in soon, I don't like driving around with no boost :-).

[16M4]

Good thing its still under warranty

[Carl Morris]

Just CPO. We'll see how that goes...

[mattsfeir]

Could be a vacuum line, but mine went slowly over time and ended up at really low boost, not sudden like yours.

Search for a thread started by me in the N54 section for how to diagnose and fix if needed.

[Bimmer This]

sounds like you got a boost leak somewhere.

[Carl Morris]

Turned out to be two things. They say there's a bad fuel pressure sensor (I assume it's the low pressure side from the logs) and they say a C-clamp broke or fell from from a wastegate actuator, hence the zero boost.

Anybody heard of that particular failure mode on the WGAs? It's supposed to be covered under CPO, otherwise I'd be looking for some RBs.

[Dackz]

Originally Posted by Carl Morris

Turned out to be two things. They say there's a bad fuel pressure sensor (I assume it's the low pressure side from the logs) and they say a C-clamp broke or fell from from a wastegate actuator, hence the zero boost.

Anybody heard of that particular failure mode on the WGAs? It's supposed to be covered under CPO, otherwise I'd be looking for some RBs.

Why couldnt you just put a new c-clamp on it if it wasnt covered?

[Carl Morris]

Yes, but I'm taking them at their word that it's a total pain to get to. My hope and intention is to never have to dig that far into it without actually upgrading the turbos. Small turbos are extremely limiting at our elevation.

[Carl Morris]

It was the front one. I paid $50 CPO, dealer is charging BMW over $1500 at the reduced labor rate for that plus the new fuel pressure sensor.

[mattsfeir]

Ouch, good thing for CPO.

Unless you were waiting for a reason to upgrade.

[Carl Morris]

Not yet. But when the CPO is gone that's all the excuse I would need. I just hope the big singles are common and cheap by then. Or at least a little more common than today.