E30 M42 swap infomation

[selespeed]

Oops I'm sorry I didn't realize. But pardon me for ignorant. What's the
function of this thing? From the parts diagram, it seems this is standard item on the e36.
So how would fitting this fool the ECU?

[Speedtouch]

The 1000 ohm resistor just gives the ECU the equivalent 'within range' signal that a working vent valve would give if the operating conditions are right, satisfying the criteria of a certain section of the computer program. Thus, the ECU is effectively 'tricked' into thinking that everything is hunky-dory.

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

http://www.ehow.com/info_12199368_mean- ... -mode.html

[selespeed]

Ok. I've read what a limp mode is. Now I checked my engine bay and found the connector is left dangling. Where is the resistor installed? All I see is just one wire with a connector socket. Also how does a resistor look like?

Thanks

[Speedtouch]

I imagine that the resistor plugs into the connector. It looks like this:



Or like this, if you just buy a basic resistor:

[selespeed]

Thanks.

Item 8 is standard BMW component that plugs into the connector?
Why does BMW make this available?

[Speedtouch]

Yes:

http://www.realoem.com/bmw/showparts.do ... =15&hl=145

It's probably one of BMW's afterthought 'bodges', such as they did on the E30, to cure a cold starting issue.

[selespeed]

Haha. Very strange they provide a quick fix in addition to the proper way of solving problem. Hmmmm BMW don't know what they're up to

[selespeed]

Hi guys, I just got a new resister original BMW item that plugged into the connector. It appears that the acceleration is now normal and I can do 180 easily while second gear and third pulls easily to 6500. I'm quite happy and will next check diagnostics to verify that the tank ventilation error goes away and to reset existing errors. And thank you both Brian and speedtouch for your valuable advice.

However, the engine vibrations persist. This is the one I described earlier most noticeably between 2000 to 3000rpm felt through the steering wheel. Any ideas?

M40 flywheel used back in m42. M40 flywheel is perfect on my old m40b16. Clutch is a relatively new LUK since march.

Thank you guys once again.

Selespeed

[Brianmoooore]

As I said further up the page, I'm not particularly familiar with your engine, and was basing my comments on my knowledge of the six cylinder engine from the same era. I know for certain that the only effect a disconnected tank valve has on the six cylinder engine is to turn the EM light on and to log a fault code. It's entirely possible that Speedtouch is right, and that on your engine it does make the engine run in limp mode as well, but it's difficult to see why this would be designed in, since a failed tank valve is no threat to any other engine component.
BMW produce this resistor for fitting onto cars which are sold in parts of the world where the emissions equipment wasn't required or fitted.
Does this engine vibration manifest itself when the car isn't moving, or when you're driving along (or both)?

[selespeed]

Brian;
Maybe BMW just doesn't want owners to pollute the atmosphere by disallowing hard acceleration.

Anyway, the engine vibration is there even when car is stationery. Say revving slowly up to 3000rpm. But the vibrations seem to reduce or disappear when I'm cruising at 4500rpm or whatever rpm higher than 3000. Vibration is there even when declutching in neutral gear. Or when I engage in gear to move off slowly gradually increasing the rev

[Brianmoooore]

Tank vent valve has nothing to do with pollution produced by the engine, however it's being driven. The system is simply to prevent the minuscule amount of petrol that evaporates from the tank in response to varying atmospheric pressure and temperature from being released into the open air.
If there's a vibration with the engine on its own, it would be a misfire, that I'd expect it to show up on the diagnostics, unless it's an unbalanced rotating engine component.

[Speedtouch]

I take it the engine mounts are in good condition?

[selespeed]

Engine mounts are new. I changed these and still doesn't cure the problem.

Spark plugs are new too since may. What would diagnostics show if there's a misfire? However, when cruising at say 4000 to 4500 rpm, it's smooth and quiet too.

Have a look at the in car video recently I drove to Phuket Thailand

[selespeed]

Brian,
I am yet to do a diagnostics. the mechanic today did not have the tool to check for me. I am asking if plug cables need to be replaced? what is the experience of users here?

[Speedtouch]

Use a multimeter to measure their resistance; all should read roughly equal (dependent on length) and under 10 kilohms.

[selespeed]

thank you speedtouch. I will check this. but as you know the vibrations exist even without load.

have a look at this https://www.centerforce.com/images/site ... de04DL.pdf

look under "Pressure Plate Improperly Balanced" page 5. I am inclined to think this may be the culprit. because when I engaged a gear and slowly revv up the engine and release the clutch pedal, I can feel the vibrations more pronounced.

even without pressing clutch pedal, vibration is there.

has anyone ever experienced?

[Jay-Vee]

Hi Everyone

About to take the plunge and source an E36 (pre-95 M42) for a swap into my '88 E30 M40.

One Big Question - does the intake manifold HAVE to be swapped to E30 type?

I know it says at the start of this thread that you have to but I've read other places you don't.
And I'm still not sure even why?

E30 M42s are rare here in Australia so this is a pretty big factor for me.

Cheers.

[selespeed]

Yes. The entire thing intake DME wires AFM etc. I've contemplated changing to e30 type intake but you'll have many headaches. The DME needs to be this type too

[jmc330i]

One Big Question - does the intake manifold HAVE to be swapped to E30 type?

No, it does not have to be but if you keep the E36 intake manifold, you will need to tackle the swap more like a M50/52 swap in terms of wiring as you will need to use the E36 loom, ECU etc.

I've swapped a complete E36 M44 into my E30, using the complete E36 intake etc.

[Jay-Vee]

Thanks guys,

I only doing some of the work myself is using the E36 loom something a professional auto electrician can wire up without costing megabucks?

I'm happy to pay a little, just wanna make sure it's feasible to throw all the standard E36 gear at my local guy for the electrics.

[Brianmoooore]

Converting the E36 loom electrically is little more than chopping off the multi pin plug that goes into the round socket next to the fusebox, and splicing an E30 one in its place.
The main problem is that you may not be able to mount the relays or ECU in their original location without more extensive mods.

[jmc330i]

As Brian said, converting the loom isn't difficult and is DIY-able with the info available on here (both the forum and wiki).

The E36 loom for mine was removed from its plastic housing and with a bit of work is now tucked away nicely under the standard E30 M40 loom cover on the bulkhead. All the relays are fitted in place under the loom cover and the diagnostic socket is fitted in the standard E30 location. I only had to shorten wires to make it neat and tidy.

The ECU placement is the only real problem. Thankfully once the loom is out of its plastic housing, there is just enough slack in the loom to get the ECU plug through the bulkhead and close to the E30 ECU mount location, but mounting the ECU will take a bit of thinking about as none of the mount holes match up and the ECU sits at an angle.

[Jay-Vee]

Thanks so much for the info, what would noobs like me do without these forums and communities!?

[silver2]

Excellent write up, thanks for your efforts, i am just about to undertake this, and replace my 318 M40 with the 318 M42. So will be using your thread as my guide.

thanks, will keep you posted how it goes

[TPS]

I've done it, easy job, well worth it IMO

[silver2]

Good to hear, im looking forward to it actually, just need to free up some time. Just to get an idea, How long approx does the M40-M42 swap take? im reasonably mechanically minded.

[rix313]

Do it over a weekend if you take your time I'd say mate

[silver2]

Hi chaps, right so ive got the M40 out and M42 in over the Christmas break. (All M42 components from an e30)


However ive come across a problem, using my M40 Gearbox and propshaft etc there is about 15mm gap between box/guibo and propshaft? Any thoughts?


ive used the following as suggested:
M42 engine
M42 engine mounts and brackets
M42 wiring loom & ecu

any advice would be greatly appreciated, thanks

[Speedtouch]

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

[silver2]

Thanks i have been through the link before.

It states that when using m40 box i will have to use m40 prop etc, which i am, i dont understand why there is a gap between prop and gearbox?

Any suggestions anyone

[Speedtouch]

Doesn't it have a telescopic section on the propshaft output flange to adjust it's length?

http://www.e30zone.net/e30zonewiki/index.php/Drivetrain

"Although the M40 and M42 boxes are interchangeable, the input/output shafts are different and so is the propshaft. This means that replacing a 318iS gearbox with the more mundane 318i unit will necessitate a change in prop."

[silver2]

"However, it is possible to adjust the length of each propshaft by a certain amount (up to 10mm) by loosening the collar nut (pictured) and pulling the two halves of the prop apart. Make sure you mark the two halves first in case you separate the prop completely"


Thanks speedtouch, yep just saw that prop is adjustable, so will try that tomorrow.


Where is best to Ground the engine?

Previously on the M40 it was from chassis to engine mount bracket, is this still fine for the M42? Where is the 318is Grounded?

thanks

[silver2]

http://www.pelicanparts.com/BMW/techart ... earing.htm

Useful How-To replacing propshaft bearing, length adjustable prop

[Speedtouch]

Thanks speedtouch, yep just saw that prop is adjustable, so will try that tomorrow.


Where is best to Ground the engine?

Previously on the M40 it was from chassis to engine mount bracket, is this still fine for the M42? Where is the 318is Grounded?

thanks

No problem - glad to be of help. Yes, your existing engine-to-body earth strap arrangement should be fine. As long as it gets a good earth, that's the main thing.

[silver2]

Great will be back working on the car in the next few days, updating as I go along cheers