M21 Engine Rebuild

Finally, a home for all you 524td oil burners out there.
Mike W.
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Joined: Feb 12, 2006 12:00 PM
Location: California Whine Country

Re: M21 Engine Rebuild

Post by Mike W. »

Preface, I don't know M21s. I don't even know M20s. But that doesn't look right.
It looks very similar to an M30 oil level sensor, which has an O ring, I'm pretty sure in the sensor, that seals to the pan. In this case you would need two, one on either side of the plastic piece. And Gadget as usual has an insight, one of those studs looks like it's cut off. But I just don't see them using a plastic shield to seal between the pan and the sensor.
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Re: M21 Engine Rebuild

Post by gadget73 »

https://www.realoem.com/bmw/enUS/showpa ... Id=11_0168

has the assembly diagram, they don't show nuts between the metal shield and the sensor, but just looking at the shape of the parts I just don't see how that would sit together right without something to keep the metal shield from bending. If it had spacer bushings or something in there it would make more sense to me.

it does appear that the studs unscrew though
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Joined: Dec 28, 2021 5:01 PM
Location: North Carolina

Re: M21 Engine Rebuild

Post by Alpinweib524td »

Looks like the wrong sensor. Grind off the three tits so the plate will mount flush against the sensor.
Here is a picture from my engine that is currently being rebuilt with original sensor installed.
https://drive.google.com/file/d/13iSn1y ... share_link
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Re: M21 Engine Rebuild

Post by z122643 »

Got it. Thanks
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Joined: Feb 13, 2024 10:52 PM
Location: Salt Lake

Re: M21 Engine Rebuild

Post by thehardcorps »

Just picked up an M21 and love seeing your build come along. I would be very interested in learning more and sourcing your rods. Do you have a company site or can I just PM you?
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