E12 Crank Position sensor

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71911
Posts: 2
Joined: Sun Aug 06, 2017 10:48 am
Location: Madison, CT

E12 Crank Position sensor

Post by 71911 »

My 1980 528i crank position sensor is unplugged and the 3 socket plug is just dangling from the 12" length of wire from the sensor. I can't find where it is supposed to get plugged in. The car starts, but runs very rough. Anyone have photos of what it is supposed to plug into? I assume there is some sort of receptacle on the top side of the engine somewhere near the intake, but just can't find it.
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71911
Posts: 2
Joined: Sun Aug 06, 2017 10:48 am
Location: Madison, CT

Re: E12 Crank Position sensor

Post by 71911 »

OK, 1/2 the mystery resolved. My son also has an E12 ('79) so I asked him to track the sensor wire on his car. So, I know the wire, plug, and metal bracket the plug is mounted in sits on a stud on the valve cover, just underneath the air cleaner. But the crazy thing is, his isn't plugged into anything either! Is the sensor necessary?
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PatinaBeforePolish
Posts: 351
Joined: Sun Jan 18, 2015 1:22 pm
Location: Baltimore, Md.

Re: E12 Crank Position sensor

Post by PatinaBeforePolish »

It’s a port for long forgotten test equipment. Not needed.
79 528i
76 530i - Stored since 1992, can it be brought back to life?
86 944- 2023 project
78 F150- Everyone needs a truck
janusz200
Posts: 11
Joined: Sat Oct 27, 2012 2:24 pm

Re: E12 Crank Position sensor

Post by janusz200 »

Hi, today I've bought the plug for this service socket, looks nice in bay but I still don't know what is this socket for - what was possible to check with this? Anybody knows?

Being curious about it I've just found this thread. To answer 71911 question I attach the photo of thermostat housing of my E24 (1980 3,5 littre M90 engine) - maybe it's of help.
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maybeillbuyit
Posts: 333
Joined: Mon Feb 17, 2014 12:26 am
Location: Vancouver BC

Re: E12 Crank Position sensor

Post by maybeillbuyit »

Interesting plug cover, I've never sen that on a car. Did you get that cover from BMW? I just tossed the one on my e12 when I did the thermostat etc. I assume the crank sensor on these cars was used in some simple diagnostic system BMW used before things got more advanced to the larger diagnostic port on e28s and late e24s. RPM, timing, maybe used in conjunction with a timing light etc. Probably didn't tell you much.
janusz200 I would suggest getting rid of that early bleeder screw as they can be a bitch to get loose if they seize vs the later 10mm nut version
1977 530i another project
1979 635csi Euro "project"
1987 635csi
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CabbageFumes
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Re: E12 Crank Position sensor

Post by CabbageFumes »

maybeillbuyit wrote: Thu Jun 13, 2019 1:42 pm ..the later 10mm nut version
8mm...
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maybeillbuyit
Posts: 333
Joined: Mon Feb 17, 2014 12:26 am
Location: Vancouver BC

Re: E12 Crank Position sensor

Post by maybeillbuyit »

:oops: Right you are
1977 530i another project
1979 635csi Euro "project"
1987 635csi
janusz200
Posts: 11
Joined: Sat Oct 27, 2012 2:24 pm

Re: E12 Crank Position sensor

Post by janusz200 »

Thanks for hint about bleeding screw. Changing the coolant last time I scaresly moved this screw and fortunatelly it never failed. You mean to machine new thread M8 in housing? Have You a photo of new screw?

I've bought this beatifull red cap at BMW. Small thing, 2 bucks and so much fun.
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Mike W.
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Re: E12 Crank Position sensor

Post by Mike W. »

janusz200 wrote: Wed Jun 19, 2019 2:11 pm Thanks for hint about bleeding screw. Changing the coolant last time I scaresly moved this screw and fortunatelly it never failed. You mean to machine new thread M8 in housing? Have You a photo of new screw?

I've bought this beatifull red cap at BMW. Small thing, 2 bucks and so much fun.
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Mike W.



1980 528i, 3.5 euro, 5 speed conversion
1981 528i, 3.6, Recaros and more. Project
1998 328is, quick and efficient, but not satisfying
2000 528iit, Vacation mobile/wife's grocery getter
janusz200
Posts: 11
Joined: Sat Oct 27, 2012 2:24 pm

Re: E12 Crank Position sensor

Post by janusz200 »

Thank you
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