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M42 swap
Posted: Mon Mar 04, 2013 10:26 am
by Racer75
Hi all, looking at replacments for the M40B18 which just expired and a serious contender is an M42 from a 318iS. Will this be a straight swap from the M40 or are there other issues (Props, wiring loom etc.)?
Cheers

Re: M42 swap
Posted: Mon Mar 04, 2013 10:28 am
by Jim320i
Re: M42 swap
Posted: Mon Mar 04, 2013 10:51 am
by TPS
I've done the swap recently & its well worth it, more power, better MPG, any help you need, please get in touch.
Re: M42 swap
Posted: Mon Mar 04, 2013 10:56 am
by magpie
i've done this swap about 5 times now,you can use many of the m40 parts inc g/box prop,rad,afm,alt,starter,p/s pump .
you need to use m42 loom,coil packs,ecu and exhaust ,fantastic little fizz bomb the m42

Re: M42 swap
Posted: Mon Mar 04, 2013 11:50 am
by Grrrmachine
Bloody hell Jim, you were in there like a whippet!
Full M42 swap is explained here:
http://www.e30zone.net/e30zonewiki/inde ... Swap_-_M42
Re: M42 swap
Posted: Mon Mar 04, 2013 6:41 pm
by Racer75
How hard is it to change from the 40 to the 42 loom?
Re: M42 swap
Posted: Mon Mar 04, 2013 6:44 pm
by TPS
Not very hard at all
Re: M42 swap
Posted: Mon Mar 04, 2013 6:48 pm
by Brianmoooore
Racer75 wrote:How hard is it to change from the 40 to the 42 loom?
The looms should remain attached to their respective engines all the time, and be removed/fitted with them.
The only connections between the engine loom and the car are the two battery connections and the 20 pin circular plug and socket next to the fusebox.
Re: M42 swap
Posted: Mon Mar 04, 2013 11:48 pm
by Racer75
Think i forgot to mention the car is running with an Auto box, i would like to fit a manual, does this complicate things?
Re: M42 swap
Posted: Mon Mar 04, 2013 11:55 pm
by Brianmoooore
Racer75 wrote:Think i forgot to mention the car is running with an Auto box, i would like to fit a manual, does this complicate things?
Not as long as you get the prop shaft from the iS, and all the other bits such as pedal box, etc. from any E30.
Starter inhibitor is dealt with by joining together a plug and socket with black/yellow wires behind the glovebox.
Re: M42 swap
Posted: Tue Mar 05, 2013 6:12 am
by Grrrmachine
Alongside the engine swap, there's also a documented guide to converting from Auto to Manual:
http://www.e30zone.net/e30zonewiki/inde ... _To_Manual
That'll give you some clue of what's needed.