e36 m42b18 swap in e30 m10b18

[kobra]

hello, i have a 1988 e30 with m10 b18 L-jetronic injection, manual transmission  and i am planing to change the engine with a e36 m42b18 engine. can someone help me with a list of all things that i need it to put the m42 in my e30? from what i read about this swap this is my shopping list:

- m42b18 e36 engine
- transmission, wiring harness, ecu and EWS ( from what engine/car?);
- upper and lower oil pan ( from what engine/car?);
- engine and transmission mounts and brackets ( from what engine/car?);
- inlet manifold ( why i can't use the e36 inlet manifold ?);
- radiator ( from what engine/car?);
- Prop-shaft- can i use the one from m10 or i have to buy another? (from what car?)
- exhaust system- can i use the one from m10?

do i need something else?

i found to buy a m42b18 from e36 mounted on e30, with m40 transmission but have a problem with idle speed ( sometimes is too low, sometimes oscillating). i don't know what to do, the problem with idle speed is scaring me (can be a major problem?). what difference is between m40 and m42 transmission regarding ratio? can i use the m10 prop-shaft with that configuration?

[Darky]

Hi

there are lots of different combinations.
The short block/bottom of engine m40 and m42 are identical. Heads are very different!
M40 sumps/ oil pans same as m42, as too are the engine brackets.
You could use e36 harness just need to change a few wires, well documented.
You need to match the inlet manifold to the ecu.
Radiator big is good m40/m42/m20
Prop shaft I don't know probably a mix and match set up. As BMW used 6 different prop flanges on there diffs.
What's the size of the m10 exhaust?

What have you got?

M40 and m42 gearboxes are the same except 3 rd gear ratio is different 1.3 to 1.6. 5 th too but now your really pulling hairs .8 to .81. The gearbox is a g240

What is the idle speed? Rpm wise oscillating? Was the engine hot cold etc

Cheers Rohan

[kobra]

hi, i give up with the engine with idle problems and i found another engine, also from e36. can i use engine mounts and brackets, radiator, exhaust system and first part of prop-shaft  from e36 to be bolt-on on my e30?

[Darky]

Hi

You will
Need m4* to e30 engine brackets
Radiator will be fine
Prop shaft will be a mix and match of the 2
Not sure about exhaust system could use m10 e30

Cheers Rohan

[kobra]

thank you Darky!

regarding wiring this engine, can somebody help me with a wiring diagram to connect e36 engine harness to my m10 e30?

[benz-tech]

Go to wedophones.com for the E36 wiring diagram,  go to E30zone for the E30 diagrams. I found these to be the most accurate. E30zone also has the C101 pinout. I can email you my copy of the x20 e36 connector but it is for a 96 ti. There WILL be differences, PM me if you think iw will help you but there are a ton of obd2 wires that you wont have. The best way is to sit down with a diagram and look for everything that passes through the x20, then match it up to the c101.

 I verified each wire I installed in the c101 by color and pin location at the DME, and then on the body side by color and pin location.  "Measure twice, cut once" is my creedo when it comes to complicated stuff like this.

Good luck. It will be a challenge. 

[kobra]

can anybody help me with the diagram for this 2 connectors? i think are the c101 connectors. first is from my car, bmw e30 m10b18 l-jetronic injection engine from 1988 and second is from an 1992 bmw e36 m42b18 engine bought for my car. i cant find it the diagrams in bentley and haynes manuals and for e30 i cant find this type of connector, only the rectangular one.

[1998ccc]

If u look closely...may need a magnifying glass depending on how good your eyes are...the pin #'s are cast into the plastic housing.  The webphones site has the ETM.  GOod luck.

[benz-tech]

I'm not trying to be a jerk, but did you read what I said in my previous post? Here it is more clearly:
E30zone.net for e30 c101 pinout and diagrams.
Wedophones.com for e36 diagrams. You may need to isolate every wire that goes through the x20 (e36, in your pic) on the diagram and find its mate on your c101 (e30 ) I can email you the 96 ti x20 pinout that is probably similar.

I just saved you hours of searching since there are plenty of useless diagrams out there, I know I used one and wired a few things incorrectly because of them.

[kobra]

On e30 zone i find only for motronic, i have jetronic injection.for jetronic i find only rectangular connector, not round. And fir e36 i have found many diagrams but are not the same.so wich is correct? Before ask i have searched.i am not lazy.but i didn't find something good. So if you can, please send me your diagram to compare with my connector.

[benz-tech]

http://www.e30zone.net/e30zonewiki/index.php/C101

This page has both the round and square c101 pinout.

Any 92-95 e36 e36 diagram off of wedophones.com should work. If you know what year your engine/DME/EWS  is from then that will narrow it down. These diagrams do include all engine choices for that year car. Choose m42 and the subsequent pages will have what you need. When looking at the diagram, a wireoff the DME will go to the cluster or other part. In the middle of that wire there will be an x20 with a pin number. Write that down and all other wire pins that go through the x20. Then cut the x20 off, solder or re-pin each wire to the c101 based on what the wire's function is. The chart I have is for a 96 318 to a 98 m52 swap so I already had to filter out the wrong wires for what I needed. I'm reluctant to hand that off to you.

[kobra]

In the link from you, motronic have round conector and jetronic is rectangle conector. My car have jetronic injection with round cinnector. This is the problem. I have the same pinout as motronic?

For e36 i dont know exactly the year of the engine because the car is from 1992 but the engine have ews and the ews have some strange improvisation already made. And i believe that is not the original engine and was changed.

[kobra]

i just finished to change my m10 engine with m42 and i have a problem, the temp gauge is not working. the needle doesn't move. before swap everything was ok with my temp gauge also in the donor car. i used e36 wiring loom, everything is verified to be connected, also the wiring in the x20 connector. how can i get my gauge work again?

[Darky]

Hi

Do you still have the 2 temp sensors? If so see if there is a difference in resistance between the 2.

You may be able to just swap the old one in.

Cheers

[kobra]

all the sensors are installed, i don't remove anything from the engine. is like was in the e36. yes, i have also  the sensor from m10 but is bigger in diameter and length then the one from m42. the e36 temp sensor is not compatible with e30 gauge?

only thing that is not connected is a cable from somewhere underneath of intake manifold with a connector with 2 pins but i don't know where to connect it because i don't have any free connector and my engine works fine without this cable connected.