m20 to m42 swap

[boostdog]

Ok guys/gals i acquired a 87 325i rolling chassis from a buddy and have at my disposal a m42 and trans from a 91 318i complete with a/c power steering ETc. ...I did some searching and didn't find any info on this...i realize it's a downgrade from the m20 that was in the car but it's long gone and i want to get the 325i running for now.

What i mainly need to know is about the wiring....any advice would be appreciated. The m20 wiring harness looks complete.

thanks
Bryan

Edit - will i have any issues with the driveshaft from the m42 using the orig. 4.10 lsd rear?

[619E30]

Couldn't help you there

[boostdog]

well thank you anyway ....i guess? LOL

[///digitalme]

you also would need a harness and ecu, i dont know about the driveshaft if they are interchangeable between 325 and 318is. engine mounts? radiator?,
i have an m42 harness if you need one...

[///digitalme]

i just saw...well if your 4.10 is small case it would be perfect for the swap...if not i dont think youll have any sort of problem though..

[boostdog]

good to hear! i have the complete donor car avail including wiring / radiator etc. so i think it should go pretty smoothly.

[StereoInstaller1]

What is the production date on the '87?

[boostdog]

i'll have to look and get back to you.

[psyber_0ptix]

the driveshaft depends on the trans you plan to run. The 318 driveshaft is a little longer since the whole motor/trans assembly sits a bit more forward compared to it's 6 cylinder counterparts. This is why late model 318 owners must swap their driveshafts when planning on a 6 cylinder swap.

getrag240 and associated shift linkage+318 driveshaft

or

getrag260 and associated shiftlinkage + 325 driveshaft.


just swap over the motor harness and dme and the rest should be fine i'd imagine.

[boostdog]

cool thanks man! well we tried to start the motor yesterday starter just spins and spins...looks like it either needs a new starter or there's a issue with the flywheel. once we get the motor out i'll troubleshoot it further.

[///digitalme]

i had that ussie with my car when i swapped in another m42 engine it turned out to be bad wiring and starter was going bad

[boostdog]

ya i think it's the starter as well...there is some wiring issues with this car..there's a couple of wires that have been chewed through...one off the fuse block ( blue wire ) and one that is hooked to a orange box on the pass side fender. any ideas what those 2 wires go to?

i think once we get the motor out i'll pull the starter and see how it looks. but at this point im thinking a m30 swap down the road soooo we'll see.

[QBANG]

ya i think it's the starter as well...there is some wiring issues with this car..there's a couple of wires that have been chewed through...one off the fuse block ( blue wire ) and one that is hooked to a orange box on the pass side fender. any ideas what those 2 wires go to?

i think once we get the motor out i'll pull the starter and see how it looks. but at this point im thinking a m30 swap down the road soooo we'll see.

B.... Sad news, the motor will not even trun over by hand. Its going to get parted.