635csi crankshaft sensor. Which one? Where? Uk

[Joe Wright]

Hi all i need new crankshaft sensor . Got one from eurocarparts uk but its the wrong one . Does anyone know where i can get it from and whats the right type?
Thanks
Joe

[ron]

Hi Joe,

Welcome to the forum.

Would suggest you put the year of car in your profile so that everyone knows what parts to look for.

Did Rob show you this link?

http://www.realoem.com/bmw/enUS/select? ... series=E24

Are you aware that your number plates are illegal? They should be reflective from 1973.

[Joe Wright]

Looks like i n eed one fr om 87 on . 235 pounds from bmw

[Ralph in Socal]

Looks like i n eed one fr om 87 on . 235 pounds from bmw

NOOOOO!! For a $60 I'll send you 2 good tested ones if you're willing to wait a few days. Regular Bell Housing Sensors are only about $80 each new. The one you are looking at is for 88/89 highlines if there is only one at the front of the engine.

I agree with Ron, Joe. You need to provide your car information so that we can help you properly.


Ralph

[Joe Wright]

Hi. Sorry gents.bmw partn o is 12521287784. Ill have to keep looking. Myc ar is an 84 635 but i believe it has a later engine hence the confusion . Definitely looking down the cheaper route.
Joe

[Ralph in Socal]

Then post a pic of the engine bay. That will provide enough to tell us what you "may" need. But it is still important to show what car you have on your sig so you wont have to continually post your car info.


Ralph

[Joe Wright]

Okay thanks ill try

[sharkfan]

I picked up a pair of tested used ones for my late 1982 635CSi last month when one gave up the ghost; £29 for the pair from ebay.

[cecotto479]

People get confused by the "crankshaft position sensor".

The pre Highline Motronic cars have two sensors performing the function of a crank position sensor. These are mounted in the gearbox bellhousing. Either can fail and cause a no start. Though when the speed sensor goes, the car often starts and then dies very quickly, the position reference sensor causes loss of spark when it fails.

The confusion arises in that these engines also have a front mounted sensor on the crankshaft pulley that looks like a crank position sensor. It does nothing in terms of the engine running. It only reports TDC to the diagnostic socket.

I've often had people seeing the wiring to this in a poor state and assuming that that is what is causing their no start.

The part number you have provided is this TDC indicator.

IT WILL ABSOLUTELY NOT CURE YOUR NO START ISSUE.

If your crank pulley does not have a toothed wheel, the sensor at the front does nothing and your "crank position sensor" is the two sensors in the gearbox bellhousing.

If your crank pulley has the toothed wheel, you have a front mounted sensor that does the work of the two gearbox sensors and no gearbox mounted sensor.

[wattsmonkey]

Hi Joe,

Need to clarify re. engine: it is NOT a highline engine, rather it is a particularly sexy "spare" M30B34 bought by someone with very deep pockets back in the day, hence the later date stamp. To all intents and purposes, it's no different from the original engine.

As per texts and posts above, the highline's management is completely different from yours.

It's always worth checking BMW prices, there are some pleasant surprises, but speed and ref sensors aren't one of them!

Just re-read Boyd's post - you need to remove one of your sensors from the bellhousing and measure it, I imagine it's the 610mm one, part no. 12141708619 and called a "pulse generator" in BMW nomenclature, otherwise the 820mm one is 12141708618. Get checking on realoem!



Cheers,

Rob

[Joe Wright]

Thanks everyone
Very confused now. The part i need is the part i gave the number of . i have it in my hand .It sits right near the front pulley and is short and stubby at the sensor end . The part numbers for cranshaft sensors bring up a sensor thats totally different in shape and the sensor end is longer and metal. Ive bought one so know its incorrect. Ive been checking oem.
Nightmare

[ron]

Thanks everyone
Very confused now. The part i need is the part i gave the number of . i have it in my hand .It sits right near the front pulley and is short and stubby at the sensor end . The part numbers for cranshaft sensors bring up a sensor thats totally different in shape and the sensor end is longer and metal. Ive bought one so know its incorrect. Ive been checking oem.
Nightmare

Joe,

READ and DIGEST the above post from "cecotto479". It tells you ALL you need to know.

#1 (12141730773)

http://www.realoem.com/bmw/enUS/showpar ... Id=12_0042

[cecotto479]

Thanks everyone
Very confused now. The part i need is the part i gave the number of. ....... i have it in my hand ....... Ive bought one so know its incorrect.

That part will not fix a non starting car.

If you don't believe me, order it and see.

The front sensor on a pre Highline Motronic engine is not even connected to the ECU. Follow the wires. You'll see it goes to the diagnostic socket.

If your testing leads you to the view that it is a sensor problem, test the speed and reference sensors. There are loads of guides on here on how to do it in a basic way.

You might find that the "wrong" one you have bought, is actually the correct speed or reference sensor - both the same - after all.

[ron]

That part will not fix a non starting car.

He is NOT referring to my above post he is referring to the part you "have in your hand".

We both posted at exactly the same time so that's where the confusion arose.

[Brucey]

Hi all i need new crankshaft sensor . ....

you sound very sure of this; whilst it is a common cause of a no-start and carrying spare (bellhousing) crank sensors is never a bad idea, are you sure that is the reason for a no-start?

BTW I am only 15 miles away and I have some spare crank sensors in the back of my car.

As others have said the one on the front of the engine (pre 6/87 engines) is purely for diagnostic purposes; it is not used in normal running because it is not connected to anything.

You sound as if you are driving yourself crazy; I am sure I can help out.

cheers

[Joe Wright]

Hello all. Thanks again .Finally getting somewhere after speaking to rob on here who used to Own the car.
The engine isnt of highline design . My mechanic has mistaken the broken lead for a camshaft sensor when it Is infact the lead that gives info to the computer . Hes looking at it again. Ill keep you updated. Thanks Bruce i Maybe in touch.
Joe

[Pod]

My mechanic has mistaken the broken lead for a camshaft sensor when it Is infact the lead that gives info to the computer . Hes looking at it again.
Joe

Maybe you should change your "mechanic"

[ron]

http://www.ebay.co.uk/itm/281938488308? ... 26_rdc%3D1

[Joe Wright]

Thankyou

[Joe Wright]

Hi all. Camshaft sensor okay so hes still looking for reasons why theres no spark. Is there any common problems people know of? Ill let you know how it goes.
Thanks
Joe

[Brucey]

Hi all. Camshaft sensor okay so hes still looking for reasons why theres no spark. Is there any common problems people know of? Ill let you know how it goes.
Thanks
Joe

you don't have a 'camshaft sensor' on that engine.

You have two sensors for normal engine running, one for crank speed and the other for crank position reference, both in the bellhousing. The third crank sensor on the front of the engine is only ever used for diagnostic purposes, and is not used in normal running.

If your 'mechanic' is calling anything on that engine 'a camshaft sensor' the first thing you need is probably a new mechanic.

You can only be 100% sure that the crank sensors are good (or at least not the only cause of the no-spark) by 'known good substitution' or by connecting an oscilloscope to them (and monitoring the waveform generated whilst they are still connected to the ECU or comparable load).

There are about two dozen different reasons why you could have a no-spark situation but (and please accept my apologies for being so blunt) it might be almost pointless to describe them to you because (on track record to date) your mechanic doesn't seem to understand how these engines work.

In the worst case, the more he 'works on your car' the more faults he is likely to introduce; you almost certainly started with one every simple fault (caused somehow during cleaning) but once someone who doesn't know what they are doing has been at it you could end up with several faults, quite easily.

There is an official workshop manual available online and it contains details of most of the diagnostic tests that are required to pin down the fault. If your guy doesn't want to read that or reads it and doesn't understand what it means then I would not recommend that you let him loose on your car.

cheers

[Joe Wright]

Hi Brucey,
Sorry that was my mistake. I meant crankshaft sensor. Hes tested them and said its fine but like you say for whatever reason he hasnt been very good on this occasion. Normally is.
Ill get him the manual and hope he gets it sorted without causing more problems.
Ill let you know.
Thanks again.
Joe

[Brucey]

I've got my fingers crossed for you. Hopefully it will get sorted out OK.

If you want a second opinion I can take a look at it you want.

It might yet be something dead simple; I can't help but think of a BMWCC thread with a no-start 6er and you know what....after about 15 pages of theorising and histrionics, it turned out that some numpty had put the main and fuel pump relays in the wrong sockets.....

cheers

[Joe Wright]

Thanks Brucey.
I hope so. The guy took the ecu out and it was damp. He dried it out but still no joy. The mystery continues.
Joe

[Pod]

Thanks Brucey.
I hope so. The guy took the ecu out and it was damp. He dried it out but still no joy. The mystery continues.
Joe

Just because he dried out the ECU doesn't mean that its fixed!