Drove my 2008 535xi the other day and had the onboard computer give out transmission malfunction message and limited power message when I was starting off at a green light (not peeling out), throws me into neutral, message comes on that driving is still possible. Pulled over, turned the car off, turned it back on, message was still there "Reduced power" and engine or transmission malfunction (one of the two, but I think it was tranny). Turned it off again, less than a minute later, turned it on, no messages, car drove great for 3-4 days.
Went for a drive, cruising 45km/h down my street, message comes back on, throws me into neutral again, driving still possible, I switch into drive and limp into a sidestreet. Very bad throttle response, feels like the car stays in second gear. Restarted the car once, message still on, twice and message disappeared and car drives great for 30-40km's. I hit all the rpms, in various gears, response is great, feels great, no unusual noises. starting off a green light, smooth acceleration this time, get to 30km/h and message comes on again, restarted car twice as last time to have the message disappear, drove it back home with no incident.
Same night went for another drive, no incident going there. 80km later, when I am about to park my car (still in drive), message comes on. I reverse park my car and turn engine off, try to do the double restart of the car, the message stays on.
Next morning, I start the car, message stays on. I drive to Part Source to get the free diagnostic reading of the onboard computer. Car is very sluggish until I get to around 55km/h. I am almost sure that it starts and stays in 2nd gear without switching gears. Get to part source and the guy connects the diagnostic tool. P0336 code shows up, Crankshaft Position Sensor.
I am wondering if anyone has had any experience with this. I've read that it could be anything such as low voltage in the battery, bad HPFP, sparkplugs, Crank sensor, Rotary teeth for crank sensor being chewed up. I bought the car 6 weeks ago, did 4k km on it since, now sitting at around 195k km. I haven't serviced it myself but the dealer that sold it to me had changed the battery on it (showed me the bmw receipt for the new battery, $170 or something in that range), had new brake pads, rotors, he changed the oil on it, front ball joints, passed safety with flying colours. So I really doubt the battery is the issue, plus the long drives in between would have charged it up no problem right?
The high pressure fuel pump is what I was fearing at first but the code should have been different for it, I think a low fuel pressure code, so I am not sure if that could be it.
Could it be just the sparkplugs and coils that threw me an issue? I heard someone write that a misfire could shut one cylinder off which would throw off the crank positioning sensor in a way.
This forum helped me with the choice of buying this BMW so I hope you guys might offer some more insight on this issue.
P0336 Crankshaft Position Sensor
