Dear Anyonewhocanhelp,

I recently started getting a CEL every time i open it up to full throttle, but only then. If i drive reasonably, there is no indication that anything is wrong - there is normal power, no idle issues, etc. The only other thing i noticed that i can't tell if it is my head is in traffic the engine stumbles a little around 1000 RPM (i had the HPFP replaced ~1 year ago).

This is a 2007MCS with a remanufactured engine ~20k miles ago.

The only code i can read is on the onboard computer that just says CC-ID027. My OBDII reader doesn't detect a code, but will clear the CEL each time and it returns to normal. With the OBDII reader and the Torque app i can see that the fuel pressure appears normal (1200psi under full acceleration, then drops to ~800psi after i let off after the CEL)

The only things i can think of are:
1) HPFP again
2) dirty injectors (don't know how to check this)
3) carbon buildup, though the engine is fairly young
4) fuel filter

The HPFP is under warranty still, but i don't want to bring it in for a bunch of money for diagnostics if that is not it...

Has anyone else had this problem, and what was the solution? What do you think??

 

Did you recently detail your engine bay? Look for water under your spark plug boots. Might find some rust, maybe time to replace. I'd also check the record valve... maybe your diaphragm is blown.

 

You need to get the code read. A reader that can read BMW/MINI specific codes may be necessary.

 

Little more info:

I just took off the intake manifold tonight and found 3 of the 8 valves junked up. I cleaned some of the carbon of with some dental tools but wasn't able to do a great job.

They didn't look terrible but certainly not great. Hopefully that is a definitive issue. If the little cleaning I did helps, I'll get a walnut blast soon.

Question- why would the valves not get carbon buildup evenly?

 

Probably due to the way that the air flows through the intake versus the way that the oil droplets flow. The intake is designed to properly distribute the air that comes in, but the oil doesn't move the way the air does.

... That is a guess, mind you, but it's at least a semi-educated one ...