Cam Position Sensor....BMW E46

[retro_racer]

Hi -

I'm losing the plot a bit here with my inlet CPS...

I have an E46 328i. When I had it I noticed a severe lack of power below around 3k rpm. (but bought the car anyway..!)

However, always noticed that running the car from cold, pretty much until the needle hit it's mid-way stopping point, the car ran much much better. Finally got round to pulling the codes and sure enough - inlet cam position sensor gone. So - ordered a new one, popped it in, cleared the code - car was perfect.

did a few drives, all around the 5 ish mile mark around town, taking the dogs out etc. lots of ignition on's and offs, car ran like a dream - felt like it was supercharged.

Then did a 30 mile drive, car got good and hot - fan on hot - (cooling system is all fine, never overheats, aux fan works fine). Parked up in Malvern, went for a walk for 90 mins, got back started the car and sensor had gone again... ran like a pig all the way home.

Anyway, I let it cool - reset the code and ran the car on the drive with live diagnostics running, revved it and could see cam angle changing through revs - so all working again. Done a couple of short and therfore cooler drives since and its still working..!


SO, I guess my question is, do you reckon the CPS is getting heatsoak damage or something? or is there some ECU parameter that is cominng in at higher temps that is chuffing the CPS up? I have the original sensor and a new one aswell as the current 3 day old one on the car at the moment... why is the heat killing it???

I never get a check light on the dash... any ideas would be good! I'm keeping a log of my journey times and engine temps at the moment to try and find a pattern!

thanks

[ch427]

I very much doubt that your sensors are the problem, i would first start by checking the wiring to the sensor plug.
Could it be a vanos related problem if your car has it fitted? the cam timing can sometimes flag a sensor code on other vehicles.

[retro_racer]

Hmm.. I didn't think it was VANOS related. Does have dual VANOS, but seems quiet and the piston moved nicely when I had the solenoid off the reach the sensor. Plus I have the BMW software (INPA?) which is pretty hot on the codes - but who knows..! May try the old BMW sensor back in to double check, I'll make sure all the wiring is mint first too.

Academic really as my Bonnet locks had a melt down yesterday and now the bonnet wont shut! Cannot face getting the slam panel out to fix so off the road until Bonnet Pins arrive. Gonna look cool on an auto touring..!

[ch427]

Your software should be capable of monitoring the sensor output just to see if the signal changes when the fault ocurrs. Was it an oem sensor that you fitted?

Edited by ch427 on Tuesday 30th July 19:21