Intermittent P0015 Code - '07 E92 M3

[Harry a29s65]

I have a manual 2007 e92 m3 on 78k miles. I've had a P0015 code get thrown twice now in the last 100 miles, which puts the car into limp mode until I restart the car. Both times this has occured after starting the car in cold weather and within 1 minute of driving. In general the car feels quite low power when below 2k revs but I have no comparison for feeling and could just be placebo - just takes a suprisingly long time to get up to 30mph when starting.

After the first occurrence, I removed and cleaned all of the camshaft sensors, vanos solenoids and non-return valves but a few days later the code threw for the second time. The car had an oil and oil filter change a few months ago and has only done a few hundred miles since. All the sensors and and valves looked relatively clean, the exhaust solenoids were clean but both of the intake solenoids had around half of the mesh ring clogged with debris.

Any advice on any other potential causes, things to check and possible fixes?


The car was purchased 20 days ago with a 30 day warranty but this was far away. If it was something easy and cheap I'd be happy to just to fix it myself (solenoids etc) to save time and effort but if it seems likely to be something more expensive like replacing the vanos adjustment units then I'd go to the effort of attempting through warranty.

- Harry

[RocketyMan]

Is it just the one code? Try swapping the exhaust solenoid right to left.

What type of debris did you find on the mesh? What did it look like?

[DrFerry]

Camshaft Vanos Solenoid
.

[RocketyMan]

OP, just incase you need to know which solenoid type it is exactly, it's item No. 1 in Ferry's post.

[Harry a29s65]

Had already taken all 4 vanos solenoids out and cleaned them.

Although the code was for the exhaust of bank 1, both exhaust solenoids were fairly clean however both intake solenoids were half clogged with debris (picture of 1 below, both were the same).

I'm having the rod bearings changed next week, will put some liqui moly in before the oil + filter are changed to see if the code is due to dirty oil. Although the car has had oil services regularly throughout its life and looking down the oil filler cap looks clean enough.

Due to the code coming up so intermittently I assumed (never assume) that it wouldn't be a solenoid fault as surely the fault would return every time I drive but I've realised this isn't based on any actual knowledge so, I'll switch the exhaust solenoids over and see if the code changes side if/when it next pops up.

Harry

[spammysammich]

The vanos system can only tolerate so much delta between variators before it complains. I’ve seen as much difference as one reporting 3 degrees different than the others yet no warning. That solenoid looks terrible, glad the filter mesh seems to be doing something.

[RocketyMan]

Originally Posted by Harry a29s65

Had already taken all 4 vanos solenoids out and cleaned them.

Although the code was for the exhaust of bank 1, both exhaust solenoids were fairly clean however both intake solenoids were half clogged with debris (picture of 1 below, both were the same). Attachment 3639465

I'm having the rod bearings changed next week, will put some liqui moly in before the oil + filter are changed to see if the code is due to dirty oil. Although the car has had oil services regularly throughout its life and looking down the oil filler cap looks clean enough.

Due to the code coming up so intermittently I assumed (never assume) that it wouldn't be a solenoid fault as surely the fault would return every time I drive but I've realised this isn't based on any actual knowledge so, I'll switch the exhaust solenoids over and see if the code changes side if/when it next pops up.

Harry

OP, thanks for posting that picture.
I think that's very indicative of the maintenance of that vehicle. Don't get spammy started on the oil change intervals recommended on these cars. Even tho there is that screen mesh there to help prevent debris flowing through the solenoid, that doesn't mean it prevented everything from damaging the solenoid bore and such.

Changing the oil to some magical brand won't fix a solenoid with excess leakage or excess flow when material is no longer there.

These engines also have similar VANOS systems to the N5X platform in that the sealing ring that rides the camshaft could also have the potential to wear into the housing causing excess leakage. The fix BMW did for this was add a teflon sealing ring instead of the metal ring, but only did this for the N5X platforms during that time. Also, this tended to happen more on the hydro-formed camshafts vs the cast camshafts in the N5X platform in my experience.

Denoted as item #3 as the rectanring.

https://realoem.com/bmw/enUS/showpar...diagId=11_4124