1995 e34 m52 swap - dual coolant temp sensor to single sensor style of m52?

[Sleepyhead97]

Is it possible to use the m52 temp sensor inplace of the dual sensor setup on the m50.

Testing the ohms on m50 sensors vs m52 sensor pin pairs 1&2 vs 3&4 show similar ohm ranges. If I can connect the pin pairs on sensor to the correct harness pigtail will the computer know the difference?




M50
front sensor 4.7
, back sensor 1.7ohm


M52 sensor
Pair 1 & 2
3.62 ohm

Pair 3&4
1.52 ohm

Seems to me BMW combined the m50s 2 sensors into 1 sensor with 4 pins . Will it work?
20230506_191611.jpg
20230506_191452.jpg

[dannyzabolotny]

That should be fine, lots of M52 swaps into E34/early E36 have it set up like that. Heck, you can even buy a premade harness on Turner that does exactly that: https://www.turnermotorsport.com/p-5...iring-adaptor/

[Sleepyhead97]

That should be fine, lots of M52 swaps into E34/early E36 have it set up like that. Heck, you can even buy a premade harness on Turner that does exactly that: https://www.turnermotorsport.com/p-5...iring-adaptor/

Thanks Danny! This looks to be a cleaner looking solution than making my own connections.

[circuit.heart]

You can convert back and forth between the single/dual temp sensors. Use the extra port on the cylinder head that outputs coolant to the throttle body - the port uses the same thread as the smaller M50 temp sensor. Meanwhile, the larger M50 temp sensor and M52 temp sensor can both screw into the same port.

I switch back and forth between styles based on whatever failed last. M50 sensors failed me recently so I have a genuine M52 temp sensor in the head right now and the Turner Y-harness.