M50 Loom on M52B28

[ben-yatess]

Hi all,

i did an m50b25 swap on my e30 and the head cracked, dont know how i only ran it once so i assume it had some headgasket gunk as a temp fix, anyway i bought a e39 528i on a whim not realising they dont have an x20 plug, so my question is can i use the loom that came off my e34 m50 with my m52b28 and ecu, going to get danthe to flash the ecu to get round the ews

Cheers

[DanThe]

No, its totally different to the M52 loom and won't run the engine anywhere near as good as the M52 stuff

[ben-yatess]

Thats a shame, thought that maybe the case though, cheers for the quick response, best go spend some more money

[HairyScreech]

That and the M52 uses quite different crank and cam sensors due to being a siemens ECU instead of a Bosch setup.
They are very different.

An M50B25TU (single vanos) ECU and loom will run an M52 just fine if chipped appropriately though, you just cannot mix and match the looms/ecus. You still have to swap over a lot of sensors between the donor M50 and the M52 though.

M50 loom with Bosch ECU
M52 loom with Siemens ECU

Also regarding what Dan said, I have a TU 413 ECU (M3.3.1) on the E30 and a MS4.0 on the Z3. They are quite similar but the siemens unit is higher tech when it comes to diagnosis and running adjustments.