E39 523i M52B25 Cam/Crank Position Sensor (Car won't start!)

[lukep88 0]

Hi all,

Long time (dormant) user - first time poster.

I've recently run into troubles with my E39 523i 1996. (M52b25 Engine)

It turns over (just) but runs really rough - almost like it's misfiring and doesn't hold any sort of idle.

I brought it to our local garage who ran a diagnostic on it - who seems to think it's the camshaft positioning sensor - but he says his computer isn't quite sure, and it could in fact be the crankshaft.

I have it booked in for a diagnostic at Coombes Johnston in Hamilton - they assure me I should get a more accurate idea of what sensor has failed.

Just to throw a spanner in the works - the car had the camshaft positioning sensor (intake) replaced November last year - so could this also be a case of a dodgy aftermarket part or are they usually pretty good?

Any advice would be greatly appreciated!

Thanks in advance!

Cheers

Luke

[Greg111 13]

Genuine parts should only be fitted, it is quite possible that the sensor has failed again, best to get checked on proper BMW diag as you're going to.

[lukep88 0]

Genuine parts should only be fitted, it is quite possible that the sensor has failed again, best to get checked on proper BMW diag as you're going to.

Thanks - yeah I'll try and get genuine parts. Are the readers fairly accurate that they have? Ie do you think it will be able to distinguish between Cam/Crank sensors?

[hotwire 352]

^^^^^ Yes they should & also be aware - genuine OEM parts can also be supplied by some generic parts wholesalers as per suppliers we use at woork. This typically in electrics.

[lukep88 0]

^^^^^ Yes they should & also be aware - genuine OEM parts can also be supplied by some generic parts wholesalers as per suppliers we use at woork. This typically in electrics.

Thanks for that. Can you suggest any decent places to source one of these sensors? Crank or cam? SD Euro only have aftermarket replica parts - would like to go genuine if possible but BMW are all $300+

Thanks in advance.

[bimmer boy 21]

Paying $300+ for genuine is well worth it. My sensor failed on my last year actually almost exactly a year ago and sent it in to BMW I think the bill in the end was around $1000 but that included a few other minor things they took care of like spark plugs etc. But once that was done and installed the sensor carries a 2 year warranty

Edited July 6, 2011 by RJS

[Greg111 13]

Thanks - yeah I'll try and get genuine parts. Are the readers fairly accurate that they have? Ie do you think it will be able to distinguish between Cam/Crank sensors?

The BMW diag (GT1 or ISID) is very acurate, reads out the fault in say the DME and then provides a test sequence to follow through to identify the fault in either the wiring, module or component (cam sensor etc).

[hotwire 352]

Thanks for that. Can you suggest any decent places to source one of these sensors? Crank or cam? SD Euro only have aftermarket replica parts - would like to go genuine if possible but BMW are all $300+

Thanks in advance.

An auto sparky - Wholesalers I am talking of only supply to trade. Not always OEM but typicaly with ign & some electrics

Edit: Can't recall exactly but I am sure the last BMW cam sensor I used retailed well under $300

Edited July 7, 2011 by hotwire

[thorburn 120]

Might be cheaper to buy from overseas

http://www.pelicanparts.com/cgi-bin/ksearc...ion=12141703277

[lukep88 0]

Wow thanks guys! So much help. Just the info I am after. What about one like this? I know it's replica - http://www.trademe.co.nz/Browse/Listing.aspx?id=388503423

I'm looking to probably sell the car in the near future anyway - so just after a fix on the cheaper side of things to do the job.

Thanks in advance.

Edited July 7, 2011 by lukep88

[hotwire 352]

Sooo.... has the CAS been confirmed as the fault? Could be expensive if it's a guess

[Greg111 13]

The CAS? E39?

[hotwire 352]

crank/cam angle sensor

[thorburn 120]

What does CAS stand for?crank ange or cam sngle sensor

Have you confirmed which sensor is faulty?

If you unplug the cam angle sensor the car should still run fine. The ecu will default into wasted spark and batch injection.

If it is getting a bad signal you could get the conditions you are seeing.

A faulty crank angle sensor could also do the same.

Do bmw check these in real time with an oscilloscope or is it all done with the obd stuff

Edit: sorry for repeating whats all ready been said

Edited July 7, 2011 by bbs

[Greg111 13]

A faulty cam angle sensor will cause the car to be very sluggish, run rough and at worst not run at all.

[lukep88 0]

Just had the diagnostic done - looks like there is a PRESENT code for the Cam Angle Sensor - so hopefully it's just that that's faulty. Going to buy a new one from BMW - think it will be worth paying the premium on this one to get the job done properly.

Will let you know the results. Cheers

[lukep88 0]

Right - just got back from Coombes - was reading a Cam Shaft Sensor - but in actual fact the oil separator valve (aka CCV) I've learnt - has cracked and the engine is getting far too much air!

That's why I found a small spring floating loose around the engine bay haha. Apparently to get to replace it they'll have to take the manifold off? Thoughts guys? Will I be ok to get this part from a wrecked and get a regular mechanic to chuck it in? Basically just need a new valve, new hose, gasket and vent pipe.

Thanks in advance

Edited July 9, 2011 by lukep88