BMW M50/M52 Engine Installations
 

There seems to be quite a lot of interest in the fitting of M50/52 engines in Cabrios and Sportsters so I thought I would start a new thread just for this subject.

Those watching the forum will know, before i've even finished my Sportster, i've gone and bought a 1998 2.8 litre M52 engine and (most) ancillaries.

I have been taking stock today what I have bought.
It's a complicated beastie so I have taken over 100 photo's today and have started figuring out what all the pipes, leads, connectors, sensors, etc do.

You can see the photo's on my Flickr site here...........
http://www.flickr.com/photos/peters-bmwmarlin/page1/
Plaese leave a comment if you have any answers, thanks.

In particular I am baffled by this bit hanging off the inlet manifold...

http://farm4.static.flickr.com/3273/...382bb8ea84.jpg

Realoem call it an 'Adjuster Unit'. What does it do? Do I need it?

I've taken off the aircon pump and alternator today but lots of cleaning to go......

cheers
Peter

Is the engine from an E46? It might be an electronic throttle. The whole intake looks a bit different from from the E36 ones. If it is electronic it should be pretty simple to convert it to manual.

Yes, its from an e46 car. September 1998. It still uses a throttle cable, i think, although there isn't one fitted. I'll have to look again at Realoem to see if one is fitted to this car.

You can see the cable mounting on the right of the throttle body here.......

http://farm4.static.flickr.com/3045/...cca7cb450f.jpg

But there is a large casing to the left that looks more than just a throttle pot! I'm wondering if it had cruise control?
Cruise control in a Sportster! :cool:

Trying to find a Bentley manual that covers this model.

yeah, I'm not sure on that one. I'm just going to go dig through my haynes manual see what I can see.

The Haynes manual makes reference to the ICV being above the throttle body, but its unclear from the images and looking at diagram it would make sense, its a valve into the intake manifold.

EDIT, nah I'm wrong part 7 on the diagram is the ICV. I don't have a Bentley manual for the E46.

I've invested in a BMW e46 Bently manual. It cost a a packet but it is huge; running to 1400 pages and a full 50cm thick!!

So now I know what the mystery object is above....
It's a valve that changes the resonace affect of the dual runner manifold. The design enhances low end torque by changing the intake air flow configuration for varying engine speeds.
At low speed the valve is shut which gives the intake air charge the dynamic effect of long intake tubes. This (apparantly) increases torque.
Above 4100rpm the valve opens providing the air volume for addtional power at higher rpm. (The manual has a lot more technical explanation if anyone is intrested :noidea:)

so now you all know..........

That was going to be my next guess, :madgrin: :becky: :lol:

Interesting I had no idea my car had such a thing!

You'd better keep your car locked at night......i've got a few bits missing :madgrin:

I had one of those but the wheel fell off :-)

Robin

:lol: not sure how much use M54B22 bits will be for you :madgrin:

For anyone interested looks like you can mate an M20 gearbox to an M50 engine....

http://forums.bimmerforums.com/forum....php?t=1147316

I might give it a try if I can't find a reasonably priced e46 'box...........

Peter

Hi Peterux.

I know exactly what your going through with an engine conversion at the minute. I'm in the middle of doing mine. New mounts, electrics and pipes all over the place.

All the best.

I've now spent many hours reading the manual and addtional material on the web about the DME/EWS system.
I have spent more time tracing out the wiring looms and could end up building a complete car to get this thing to work.

So then I started wondering how clever this ECU really is?
It has a control line for the Fuel pump relay, one for the main DME relay, one for the starter solenoid and finally one that interupts the ignition coil packs (called an uploader relay).
I am wondering if all of these are 'forced on' or simply bypassed (eg starter solenoid direct from the ignition switch) will the ECU still drive the ignition coils, switch the injectors and drive the VANOS, etc.

Or is it smarter than that?

Do we have any BMW design engineers (or maybe a car thief) that can help??

I dunno the answer to that one, I seem to remember reading that it sends a code around but I may be wrong!

I looked at the ECU, control and security on mine and like you, found that for the security alone, you would need dials for example to comply. So ditched the OEM one and went aftermarket.

I was also maybe a bit more lucky. The VVC on the VAG is for emissions only. So do not need to run this. Not sure on your setup with the VANOS though.

Hi Peter
Have also spent many hours on my wiring! I don't know exactly how similar your DME/EWS is to mine, but I'm still working on how to interface these with the rest of the wiring loom.
I'm going to try using the speed sensor signal from the switch on my rear diff (E36).
Found the crankshaft sensor which might operate the rev counter (?)
Will try tapping into the oil level and oil pressure wires (from the DME Module 3).
Theres only a couple of wires I think I will be using from module 4, the fuel relay and the EWS wire. There is a coolant sensor in there but I'm not going to use this.
I've been trying to simplify all the wiring down as there's absolutely masses of it, mostly too long, will put a pic up.
I will be ready to test it out in a couple of months :) so I'll let you know if it works!!
Cheers
Tim

Hi Tim,

yes, you can waste hours cross referencing all the diagrams!!

1. I used the e30 speed sensor on the diff for my speedo and it works fine.

2. On my M20, the rev counter is connected to the coil but the M52 has 6 individual coil packs so not sure yet where to get the feed. I'll be intrested to see if the crankshaft sensor works. My engine also has a vacant space for a sensor at the front of the cranshaft behind the fan, so that may be an option but not sure if the signal from a crankshaft sensor will be enough to trigger the rev counter? There must be a pin on the ECU that is RPM??

3. My oil pressure gauge uses a screw on adaptor between the oil pressure switch and the block, so I'm hoping it will also fit the M52. I didn't bother with the oil level sensor on the M20, its for people who don't know how to open the bonnet :wink:

4. I agree that the important wires on Module 4 are the fuel pump and EWS connections (also the OBD2 connections, maybe?). I'm going to experiment with them, but dont have this bit of the loom :doh:

5. My current radiator fan runs from a copper pressure bulb inserted in the top hose, so for simplicity I will stick to this, although the engineering eloquance(sp?) of using the BMW sensor and ECU does appeal!

My wiring is even worse because it was from an automatic so it has all the autobox cables as well!! I'm hoping most of this can be cut out.

Happy building!


Peter

Hi Peter
1. Silly question but of the two pins on the rear diff speed sensor, is 1 an earth (or ignition live??) and the other sends the signal? (my wiring diagrams are for E38 onwards, and the E36 Haynes manual doesn't cover it)
2. No, I'm not sure either, but I think the relevant pins for the crankshaft sensor are 8 and 21 on Module 3. There are also some possibilities for pins 36 and 37 on Module 4 but not sure about these. Also pins 2, 11 and 21 on Mod 4 go to the instrument cluster but I can't find out exactly what they do?
3. Was going to use pin26 on Mod 3 for the oil pressure. My rear fuel pump instructions suggest it should be wired to the oil pressure switch for safety reasons. Did you do this ?
5. I agree that the BMW sensor would have been nicer but I'm doing the same as you because (i) it seems easier (ii) the original sensor connector was already sheared off when I got the engine!
Good luck!
By the way, if anyone is interested, I have a possible donor vehicle available - S-reg, 528i Touring, 156k, runs superb, bodywork not great and various interior niggles, only drawback is its an automatic.
Tim

Tim

The rear speed sensor is a "hall effect" device and requires two signal wires. Neither should be earth or live. As I remember......

Robin

Hi Tim,
OK, some further comments/answers... (there are no silly questions :wink:)

1. I ran a twisted pair of cables from the diff. sensor all the way up to the speedo. I think I grounded one side, near to the dashboard, to avoid the whole thing acting as an aerial. Initially, I got some intermittant readings (luckily not during the SVA test!) which turned out to be a poor connection between the sender and the plug in connector. I took the sensor out and soldered some leads to the terminals and then filled the void with silicone rubber. No issues since doing this.

2. Yup, pins 21 and 8 (Module 3) are the crankshaft sensor but it's not a simple device as it also has a postive battery supply to it to pin 3 of the sensor. From my diagram it looks like the signal lead is Pin 2 on the sensor (yellow). But thinking about it, the crankshaft sensor will generate too many pulses for a rev counter? Pins 36 and 37 are the CAN data bus so suggest we steer clear of those for now.

However, I have found a reference to a 'Speed Signal' - Pin 17 Module 4 to the OBDII terminal, that might be worth a try?

3. Not heard of wiring the oil pressure switch to the fuel pump? I guess this is a safety feature; No oil pressure = cut fuel supply = stop!

I guess we had better get out to the garage and start testing some of these theories :smile:

br

Peter