M42 into 86 e30?

[NightOwl]

Hello! Anyone have any guidance on installing an m42 into an early e30? Any wiring required? I know this is a bit of a weird request but it’s what I’m going with so any help is appreciated. 1986 325e sedan swapping full drivetrain from 1991 318i Manual sedan. Sent from my iPhone using Tapatalk Pro

[varg]

It's essentially the same as putting a 325i drivetrain in it because drivetrain swaps are pretty much plug and play between late 318i and late 325i. You'll need a C101 adapter with the correct pinout, which would be the same as a late 325i pinout. Swap the cluster too. There is a lot of information available on the wiring involved in doing 'i' swaps in etas/early cars, if you search almost all of it will apply to this swap. Download the ETMs, that's the first step.

[downforce22]

I've installed one in an 84 318i. You need to adapt to the round c101 if yours is square and you need to change coding plug on cluster, wiring in glovebox to get tach to work etc etc. Its not hard but there are several smaller things you have to change

[ForcedFirebird]

86 should have a round c101, so it's basically plug and play as others mentioned. You will need to use the m42 drive shaft if using the g240, along with the m42 shifter setup.

The biggest thing to worry about is using a late engine in an early car, the #20 pin in the c101 can be either ground, empty, or power - so - if they are mixed up, you will let the magic smoke out of the engine harness (and some of the body harness).

[e30sh]

C101 is plug in other than pin 20. Remove that from body side harness. C101 tach and eco need to run to C104 above glovebox to get those signals.