m30 swap into a 84 325e

[curtis_luu]

Hey guys! As the title says im moving my donor into my 84 325e.

My m30 is from a 1989 535i Automatic. I have a pretty decent understanding of all the steps involved in the swap but the wiring is daunting.

1. Does anyone have any pictures of the modifications required to the automatic harness to put in a five-speed? From what i know there needs to be a wire moved within the automatic transmission connector to supply a constant voltage? (safety park?)

2. Does anyone have a kind of apples-apples comparison of the modifications needed to the c101 to make my m30 wiring harness be able to connect to my 84 body harness?
ex) pin x --> pin y

Thanks r3v! Hopefully starting the swap soon when i am able to source a trans and my mounts arrive.

[MR 325]

I would recommend ditching the auto M30 harness all together and using a late model E30 M20B25 harness. You will need to re-loom the M20 harness in a couple of places but it will not need any cuts or extensions contrary to popular belief. You can disassemble the M20 injector harness and hide the plugs in the M30 injector harness housing.

Here's how to wire an adapter from your old style harness plug to the round C101.

[Mr. Burns]

^^this.

this thread-->http://www.r3vlimited.com/board/showthread.php?t=354642

post #72 of this thread-->

http://www.r3vlimited.com/board/showthread.php?t=354642

although it IS certainly possible to stick with your M30 auto harness, be prepared for some setbacks.

not only will the M20b25 harness be cleaner, it will also be easier for install

my M30 also came from an automatic car and after some struggles I decided to remove the lot and just use an M20 harness as many other had suggested.

*I'm not sure what the 1984 eta's had for ground sources, you might have to get creative in some aspects if they differ from later modeled ETA's


good luck and nice to see another Canadian doing an M30 swap!

[curtis_luu]

Guess i'll be looking out for a late m20 harness!
As far as the modifications to get it to work...

m30 computer or m20 computer?
Think i remember something about changing a coolant sensor to a brown-top?

Thanks again!

[curtis_luu]

Pic of engine!

[Andy.B]

Use an m30 computer. It will plug right in to the m20b25 harness.
I went the m20b25 harness route with my m30 swap, and I did end up having to cut 1 single wire, only because it was so wound up in other wires in the harness it was easier to just cut it to free it. Other than that, like others have said, just cut the plastic wrapping off (carefully), and route the wires where they need to go, then re wrap the harness.

Keep the single wire temp sensor from the engine you are removing from your e30 (the single wire sensor feeds the instrument cluster, not the DME). Keep the m30 sensors for everything else.

[Mr. Burns]

Guess i'll be looking out for a late m20 harness!
As far as the modifications to get it to work...

m30 computer or m20 computer?
Think i remember something about changing a coolant sensor to a brown-top?

Thanks again!

the m20 harness will fit the M30 ECU (179)

I would highly recommend to buy the M30 DIY swap guide that R3V's very own FrankM wrote a couple of years back
I bought it and it's really helped me along the way.

cheers
Ryan

[Andy.B]

I would highly recommend to buy the M30 DIY swap guide that R3V's very own FrankM wrote a couple of years back

I second this. The hours of googling and head scratching that this document will save you is incredible.

[curtis_luu]

Thanks guys! Huge help - I'll try to update this thread with pictures when I begin my swap.

[uturn]

Having an '84 chassis e30, I think you'll have to make some mods to use the newer trannys because of how the shifter carrier changed for later cars, but if you get an older tranny you should be fine.

[curtis_luu]

You mean the shift linkage? I've heard that the early style ones (plate style) can be cut and welded to fit. As for the new style, I've heard that the UUC short shifter fits or you can use the 325i selector rod.

Anyone confirm on the options I've got?

[SketchyRex]

Just get the ecs 325i shift carrier, cut your linkage, and replace the bushings, have you decided what tranny you are gonna go with?

[curtis_luu]

It all depends on what I can find.
No parts cars have popped up in a couple months - I'm starting to look out of province for something!

[SketchyRex]

The early model g240 tranny is an option if you're willing. Use the stock flywheel and upgrade clutch and you're in business. Then you just gotta figure out your driveline.
I was able to make a 318ti manual driveline work.

[curtis_luu]

Sourced a transmission from an 89 535i
Still gathering some parts; but hope to start the swap in August

will update thread when i do. (with pictures!)