Any idea what would cause these codes? Doesn't trip check engine light but during cold start you can hear chattering that goes away. Runs fine after that

 

BMW codes 3408 = P15A1, Oil Pressure control valve: sticks when under maximum current (minimum oil pressure).

MEVD17.2-BN2000 for N55

Oil-pressure control valve, mechanical: hangs in fully energized position (minimum oil pressure).
The diagnostic function monitors the oil pressure.
Engine Oil Pressure Control, Mechanical, Solenoid Valve Sticking In Fully Energized Position (Minimum Oil Pressure)
The fault is recognized when the oil pressure remains at maximum level despite targeted application of voltage to the solenoid valve.
Potential problem source(s):- Oil pressure control valve defective
Oil pressure control valve defective.
- Replace oil pressure control valve

33FE = P15A0, Engine oil pressure control static: Engine oil pressure to low, backup mode.

N55
Engine oil pressure control, static: oil pressure too low, emergency operation
Engine Oil Pressure Control, Static, Switchover To Limp Home Operation Because Engine Oil Pressure Too Low in Map Operation
the oil pressure drops below a defined level in relation to oil temperature and engine speed.Potential problem source(s):- Defect in wiring harness between oil-pressure sensor and DME
Defective oil-pressure sensor- Oil pressure control valve
- Check wiring harness between oil-pressure sensor and DME
- Replace oil-pressure sensor
- Replace oil pressure control valve
- Replace oil pump-

 

N55 same as n18?

 

N55 same as n18?

 

No, it's not, or it would have the same number.
For diagnostic purposes, it should give you a bit more info though.
It seems like the solenoid/wiring harness to it is a common problem. That would be a good starting point to check.

 

The oil pressure regulating solenoid is a common issue on the CMS ALL4.

Being am ALL4 system, it's a bit more troublesome to replace. The transfer case needs to be shifted to the side a tiny bit to remove 1 oil pan bolt.

 

Of course it does.
Why do engineers hate mechanics so much?

 

That being said, how the fudge do we move the transfer case, to be able to remove the oil pan? Asking for a friend....

 

The "easiest" way is to remove the intake manifold. Once it's removed, you can see the top 2 18mm for the transfer case bracket. Also, gotta remove the 13mm axel bracket. Tight but doable.

 

Thank you friend. Was just about to grind a 1/4" drive 8mm socket down to a thin wall and hope for the best... I'll try it your way as the intake and head are off.
EDIT: Sorry for thread hijacking.