changing engine

[jasper25]

looking to know if it would be pretty straight foward swapin my 1987 320i engine and dropin in a 1988 325i sport. will i have to change all the wiring etc, etc?

[clarko74]

It should be pretty straightforward, I have done this swap and had never done an engine swap before.

The pre-facelift 320 uses the jetronic system whereas the 325 (and all 6 pot facelift models iirc) uses motronic, so yes you will have to swap over the engine loom. This is quite straightforward though: unplug the ecu from under the dash, feed the cable through the bulkhead into the engine bay, unplug the big round plug by the fusebox and the engine loom comes out with the engine.

[jasper25]

straight foward as that then, havnt even looked under the dash yet, does it have to come out? i got the ecu(brain) with the 325i sport engine dont think i got the loom though. noticed that the distributor cap is at the front of the new engine rather than the back, does this make odds, although i dont think it does.so anyone else done many of these engine swaps, state the info, the more the better!

[Ziggy]

Moved to the engine swaps section

[Jhonno]

Dont pre-facelifts have a different type of engine loom plug?

[zaust]

Dont pre-facelifts have a different type of engine loom plug?

Yes but an easy swap and better running too once done.

[jasper25]

would it be an easy swap? any info would be appriciated! its going to be a long winter!!

[e30_Turbo]

I've done the reverse, B25 out, B20 in before and it's not bad at all, removing the entire engine loom with the engine at the big plastic plugs is the way to go.

Just swap like for like, it's the same parts just different versions, although alarm systems and other various aftermarket wiring can cause a headache.

Personally I found removing and fitting the M20, gearbox attached, was quite fiddly and I needed more hands ( and feet ) than I have on my own, get a helper, I will next time.

A good crane is a must, M20's are heavy and I'd hate for anyone to get hurt doing these things, my crane decided it didn't want four wheels anymore and popped on off with a B25 flying high, nearly dropped it on my wing, managed to save it without damage.

Good luck, it shouldn't take long at all, it's very satisfying afterwards.

[jasper25]

thanks lad,