1989 e34 m20b25 into an 1986 eta

[e30.4.life]

I just received a donor 1989 525i with a recently rebuilt m20b25.

I have a 1986 325es. The eta motor has over 255k and it burns and leaks lots of oil and is in desperate need of being rebuilt.

I want to take the m20b25 out of the 1989 525i and swap it into the 1986 325es.

Has anyone ever done a swap like this? (e34 i motor to an eta)


I would really appreciate any feedback.

One of my main concerns is finding the appropriate wire harness. From what I have read I think I should try to find a 1987 325i wire harness to mate the 89 m20b25 to the 86 325es. Is this correct?

I figure once I have the m20b25 out of the 525i then it's just like any other m20b25, and if I want to do an eta to i swap, I should find a m20b25 wire harness from an e30 that is as close to the recipient car's model year as possible. In my case, with a 1986 e30 eta, I should look for a wire harness from a 1987 325i or is. What do you think? Am I on the right path?

What am I missing or over looking?

Lastly, what else should I scavenge or use off of the 1989 e34 for the e30?

Any and all thoughts/opinions are welcome. Thanks! :):)

[euroshark]

You might have better luck in the "Engine and Drivetrain" > "M20" section.

[e30.4.life]

Could one of the Moderators or Administrators please move this thread to the m20 engine sub section? Or should I double post this thread in both sections? Thank you!!