ideas please

[ianst0028]

ok so i bought my x5 on a whim .... our audi allroad had been written off and this x5 showed up on ebay
(also Mrs loves x5's and has always wanted one)

i Knew when i bought it that it hadn't been looked after very well recently but as i work in a motor factors and am quite handy with the old spanners i wasn't too worried

so far the x5 has needed
coil packs (i did the 6 even though she only needed 3)
plugs (lpg specific ones)
both rear ball joints (the ball joints are cheap the tool isn't)
all the arms/ links on the back (well when its apart might as well change it all)
mass air flow and idle control valve
service with Valvoline oil

but after i've done all this i still have a random issue... there is no set millage to it, no set of conditions that will trigger it
every so often i get the abs warning light the brake warning light and the dsc warning light on and it goes into limp home mode
if i stop and turn the car off lock and unlock it then start it again it vanishes
it doesn't throw any fault codes up when it does this (and I've put it on 3 different diagnostic platforms)
but the strange thing is that if i unplug the mass air flow then it runs fine all day long (week long too) without throwing up the 3 lights and limp home

I've tested the maf as recommended by the manufacturer and its well within the expected values

apart from this little issue i absolutely love the car

so anyone got any ideas ???

[andym3]

Have you looked at the camshaft position sensor? 

[themoog]

My old 6 pot E39 did that. I ended up replacing the crank sensor and the abs module.

[Pinewood]

Yep the crank sensor most likely. Had the exact same issue with my 6 cyclinder E39

[ianst0028]

that makes sense tbh i had a laguna that had a million issues all down to a crank sensor

ive got them both in work so i've got an idea of what i'm doing tonight

[cooa99]

I had a similar issue with my golf tdi.

replacing the fuel filter and injector wiring harness worked ... though not sure which was the culprit