E30 M42 swap infomation

[PiLLLe]

If you got an e36 manifold you can fit it with minor adjustment I cut out about 2 3cm out of the bottom part of the exhaust and welded it back with slightly different angle

[Roysneon]

So all I would need to do is modify the exhaust piping? So long as it will clear the steering I'm good!

[PiLLLe]

I found that easier than finding an orignal m42 e30 manifold

[DHFiS]

The engine sits further back in the E36 so the sump is different. On the E36, the resevoir is at the back as opposed to the E30 which has it at front. This causes it to smack the sub frame.

Is there any problem with the oil pick up point if you swap sumps?

[rix313]

You have to fit both the E30 spec upper and lower sump pans so no issues

[Jos]

Minor mod to the exhaust manifold? I had to cut mine back and pretty much start again to get it to clear the steering bush. Was quite a lot of welding...

PiLLLe - do you have a pic of what you did with yours?

On hindsight I would replace the steering bush with a single bar and avoid the issue!

[Human]

Very helpful write up thank you !!!!!

[joeseth]

Hi guys. Im in the process of buying an m42 and have a few questions about what's needed.

My car is a 89' 318i with the m40 engine and im buying a m42 out of an e30.

1. Is the m42 chain or belt driven?
2. The guy said he has the original coil pack so i guess that will be fine? Just need brackets.
3. Do i need the m42 afm or can i use the m40 item?
4. Did i read that the m40 flywheel was lighter than the m42? Or is it the same?
5. Is there any difference in diameter of the m42 exhaust or is it just the downpipe that is a different shape? Im getting the manifold with the engine but not the rest of exhaust.

Help on any of these will be appreciated. Cheers, Joe.

[Jos]

1) Chain but check the tensioner as this can fail and is in effect the same as a beltbreak
2) coilpack is fine, you'll need a bracket on the driverside strut tower
3) Either or, both should work.
4) They are the same/interchangable, unless it's a dualmass on the M42 which is doubtful
5) Need the downpipe too as well as manifold. M40 exhaust won't fit directly, e30is exhaust is needed unless you fancy welding.

[joeseth]

Cheers jos! Very helpful!
I know the part numbers for the coil pack brackets are on here but anyone know the price roughly from dealers? Or should i just try get it 2nd hand?
Wouldn't mind lightening the fly wheel while i can if it makes much difference.
I'll try get atleast the down pipe, if not whole exhaust, if i can.

[rix313]

I put the part numbers for the coil pack brackets are in the first post of this thread.

[JdmFanBoy]

I'm probably being stupid but I'll ask anyway, mines an M40 but after ruling out M20 due to fuel consumption and my love for 4 pot engines I've decided an M42 is better suited to my needs.

What's the cheapest and easiest way to swap in an M42 or M44?

I mean using as many parts that are already on my car like the gearbox, rad etc..

I keep seeing cheap M44's so is that an option? I know its a little bit trickier but could it be a better option in terms of money?

Any help super appreciated

[blademankiller]

hi all need some help plz i have fitted a m44 in my e30 i am using a m44 from a e36 i am using my old gearbox and prop the the gearstick will not go back in ??siting finny will not go in gear to???some help if you can plz.....

[joeseth]

A quick tip to for anyone doing this swap. It is a good idea to do the throttle body heater delete at the same time as I managed to use pipes from the m40 I was taking out so didn't have to buy a single thing. They all worked well and look neat!

[Grrrmachine]

This guide has now been immortalised in the Wiki:

http://www.e30zone.net/e30zonewiki/inde ... Swap_-_M42

I've taken on as many of your comments on board, but if there's any errors omissions then send me a PM and I'll get the article fixed.

Big thumbs up to rix for writing the main content.

[baggimodo]

Engine mounts seems to be a point of contention....

which are the compatible ones?

Do the E36 M42 ones fit, with/without modification?

I would rather use the hydraulically-damped ones but at £50+ each, may make do with the rubber ones for the time being.

What has everyone here used?

Thanks in advance.

[PieterE30]

Hello,

I have a 316 carb (90 hp) E30 1988 now and wont to put in an M42 engine. The engine is also from an E30
Can anyone tell me what do i need to change ?

Off cours i know i need to change the gearbox, engine, exhaust etc,

For me, its more the electrical part I have questions.

I found this on this site, but its not all clear.

*Wiring loom requires a swap (2 wires, oil and temp ned swapping) and there is a LIVE off the engine loom the goes directly into and EARTH on the multi plug! (i have it unused on my car the m10 loom and m42, possible fuel pump ign live tho)

The wiring loom does cater for an intank fuel pump but on my car i have seperate wiring to act as an immobiliser, therefore thats why my return pipe is 't'pieced back through the filler neck breather

Can anyone explain this a little bit more please? Pics?

Also, i need to mount a inline fuel pump. How much pressure do you need at the front at the engine?
Return fuel pipe, how to mount this? Pics?

Thanks! Pieter

[fastandloud]

I have an 1986 318i with an m10 engine do I need to change the fuel tank and fuel pump to fit an e30 m42 engine

[Brianmoooore]

No, the existing ones will work fine (assuming they work at the moment). It's with the M10 engined E30 with a carb. that a problem arises; there's no cup fitted into the bottom of the tank around the pick up to prevent fuel surge.

[rix313]

I have made some revisions to the first post and will be making a few more of the next couple of days so the information that has been gathered through this thread is included.

[sanitroc1]

Hi Rich , a few other things that I found doing my swap using an e36 m42 .
E36 throttle body is the same stud pattern as the E30 manifold but the TPS points toward the head not away as the E30 one does and the plug won't clear .
If you are going for the OEM look for the drive belts the M40 pulleys do not work as the crank pulley has a different offset to the M42 one . This means you need the crank , water pump , alternator and power steering pulleys ( thanks Phil ) .
The crank and cam position sensors wires are longer than E30 ones and the crank sensors plug has different locators so will not fit an E30 engine loom but it looks like the M40 one will .
The E36 M42 and E30 M40 injector rail has a different bolt to the E30 M42 so won't bolt to the manifold .
The injector electrics may fit from an E36 M42 to an E30 M42 engine loom but mine came with the plug cut off , but an M40 one won't as the plug comes out under the throttle body and not at the bulkhead end .
The heater pipe from the back of the head to the heater needs to be M42 as it comes from the side of the head not the back as M40 does .
If fitting an E30 318is radiator you will need the third hose that runs from the radiator to the plastic pipe under the inlet manifold as the outlet on the radiator is closer to the chassis rail .
And finally the servo pipe on the E30 M42 has a straight non return valve the E30 M40 has a right angle elbow , it will fit it just looks wrong . Thanks Steve .

[Jay-Vee]

Hi Sanitroc1 (Steve), great tips.

What was your solution to the TPS pointing the wrong way?

How about with the injector rail bolt?

Would be good to find out all these hidden surprises before I get to them ;)

Cheers.

[selespeed]

hi;

I have a e36m42 1994 swapped into my e30m40b16. it didn't go very well. after installation, I immediately experienced the following:

1. engine vibrations most noticeably from 2000 to 3000 rpm;

2. loss of acceleration when you floor the pedal - it just doesn't want to revv up. when accelerating from 2000 to 4500 it takes a long time as if there is something preventing it from going forward with periodic flat spots at 4000 and 3200 rpm.


the complete e36m42 engine with its wire looms, ecu and afm are swapped. the only sensor that is not connected is the one that connects to the fuel tank evaporator because e30 doesn't come with this. so this one is left disconnected.

I am now at my wits end as I have tried a couple of things but yield no results...

1. cam crank oxygen ping sensors are all changed to new. tps icv are all replaced. coil units also tested but still exhibit the same symptom. but the loss of acceleration is still there. there is no linear power delivery!

2. new engine mountings with hydraulic engine mounts and brackets meant for e30m42 are used. but engine vibrations still exist. then engine vibrations seem to go away slightly after 3000rpm. and while driving it is otherwise quite "smooth".

6 months later, the clutch bearing failed - melted bearing exposing the balls. I have never experienced this at all. could incorrect fitment of fly wheel (single mass m40) and clutch be the cause of vibrations? (gearbox comes from m40 getrag 240)

Questions:

a. what is the probable cause of loss of acceleration? could it be due to insufficient fuel pressure? afm or what? when I floor the pedal wanting sudden power, the power just doesn't come on. is there any way to check the fuel pressure? btw, I have a set of new NGK bkr6equp plugs though.

b. engine vibrations could it be due to fitment of flywheel and clutch. I have a new clutch fitted in march 2014 but it is still same problem.

c. I used the m42 e36 TB and its afm + m40 air box. the e36 air box is too big to fit in the engine bay. for those who have "modified" this I would like to see the pictures.

these have been major problems for me since 1 year ago and I don't know what else to do to fix these... so please help!

thanks.

selespeed

[selespeed]

hi;

I have a e36m42 1994 swapped into my e30m40b16. it didn't go very well. after installation, I immediately experienced the following:

1. engine vibrations most noticeably from 2000 to 3000 rpm, felt through the steering wheel;

2. loss of acceleration when you floor the pedal - it just doesn't want to revv up. when accelerating from 2000 to 4500 it takes a long time as if there is something preventing it from going forward with periodic flat spots at 4000 and 3200 rpm.


the complete e36m42 engine with its wire looms, ecu and afm are swapped. the only sensor that is not connected is the one that connects to the fuel tank evaporator because e30 doesn't come with this. so this one is left disconnected.

I am now at my wits end as I have tried a couple of things but yield no results...

1. cam crank oxygen ping sensors are all changed to new. tps icv are all replaced. coil units also tested but still exhibit the same symptom. but the loss of acceleration is still there. there is no linear power delivery!

2. new engine mountings with hydraulic engine mounts and brackets meant for e30m42 are used. but engine vibrations still exist. then engine vibrations seem to go away slightly after 3000rpm. and while driving it is otherwise quite "smooth".

6 months later, the clutch bearing failed - melted bearing exposing the balls. I have never experienced this at all. could incorrect fitment of fly wheel (single mass m40) and clutch be the cause of vibrations? (gearbox comes from m40 getrag 240)

Questions:

a. what is the probable cause of loss of acceleration? could it be due to insufficient fuel pressure? afm or what? when I floor the pedal wanting sudden power, the power just doesn't come on. is there any way to check the fuel pressure? btw, I have a set of new NGK bkr6equp plugs though.

b. engine vibrations could it be due to fitment of flywheel and clutch. I have a new clutch fitted in march 2014 but it is still same problem.

c. I used the m42 e36 TB and its afm + m40 air box. the e36 air box is too big to fit in the engine bay. for those who have "modified" this I would like to see the pictures.

these have been major problems for me since 1 year ago and I don't know what else to do to fix these... so please help!

thanks.

selespeed

[Brianmoooore]

You don't mention connecting this car up to a diagnostics program. That would be my first move.
You say you've left the fuel tank vapour system disconnected - I take it you've plugged the port in the inlet manifold where it was connected?
Fuel pressure is easily measured, either by connecting a pressure gauge to the shrader valve provided on the fuel rail for the purpose (if fitted), or by tee-ing it into the supply pipe to the rail. Cheap gauge kits are on ebay for about £10 or so.

[selespeed]

No. It's not connected. I don't see where this should be connected to??? The diagnostics shows this error constantly. But the mechanic says this is ok. Should I be concerned? The error is alway something like fuel tank vapor error not connected or something...

[Brianmoooore]

If you've removed the tank vent solenoid valve and haven't plugged the rubber hose that goes from it to the inlet manifold/throttle body, then this will give you a lot of the symptoms you describe.
The tank vent fault code is caused by the absence of the solenoid valve. The logged code doesn't cause any running problems, but it will turn on the EML warning light, if fitted. A resistor fitted in place of the valve will fool the ECU, and is actually available from BMW, for use in markets where the emissions equipment wasn't fitted.

[selespeed]

The inlet to throttle body is plugged. And the electric socket is left hanging disconnected. What is EML warning light? Can you tell me where I can get the resister? Is there any part number associated with it?

Thank you for your guidance. Appreciate it very much.

But would this cause problem in acceleration?

[Speedtouch]

EML = Engine Management Light.

The ECU is probably stuck in limp mode, which will most definitely affect acceleration.

[selespeed]

How do I fix this problem? You mentioned the resister. Where do I get it?

[Speedtouch]

Sounds like you need a 1kilohm, 1Watt resistor, according to this thread:

http://forums.bimmerforums.com/forum/sh ... lve-delete

Readily available from the likes of Maplin/CPC-Farnell, RS, etc.

[selespeed]

Thanks. I'm in Singapore. Doesn't say where I can get this resister. Is this a generic thing? Any pictures?

[Brianmoooore]

Part # of the resistor is 13 90 1 734 469, and is available from BMW. Last price I have is about £3.
1000 ohm 1/2W resistor will do the same thing at a fraction of the cost, but obviously won't just connect to the existing plug.
I've no direct experience of the M42 of this age, and am drawing on my knowledge of the six cylinder engines of the same era, where the absence of this valve/resistor turns on the EML, but does not affect performance.
Actual dissipation in the resistor will be a maximum of 0.15W, so 1/2W is more than adequate.

[selespeed]

Thanks. You said absence of resister won't affect performance? But earlier you also
ECU runs in limp mode thereby affecting performance???

[Brianmoooore]

Thanks. You said absence of resister won't affect performance? But earlier you also
ECU runs in limp mode thereby affecting performance???

Speedtouch said that, not me.