M52 harness questions

[MyNameIsOllie]

Hi everyone,

With the bodywork on my 316 finally in a good place, I'm moving my ambition to getting rid of this engine for something more fun.

My main question is which donor car to buy: a 728i from 95-98, a 528i from 95-98, or just go down the M50 route (despite the fact that I'm finding it hard locating a good, lower mileage engine/donor car at a reasonable price.)

If I was to get an M52 single Vanos, which harness and ECU should be used in conjunction with the M50 manifold? Also, what if the M52 was from an auto?

I know that's a lot of questions, but I'm struggling to find a detailed answer to them.

Many thanks,

Ollie

[joeyb]

I used an E36 328i manual.

Had EWS deleted from ECU and cut / adapted loom to work on E30. Fitted in M50 inlet manifold. I think an Auto loom would work but needs more cutting away?

[MyNameIsOllie]

I used an E36 328i manual.

Had EWS deleted from ECU and cut / adapted loom to work on E30. Fitted in M50 inlet manifold. I think an Auto loom would work but needs more cutting away?

Yeah that’s what I figured, I assume your 328 had the single vanos engine too?

So would the best move be to get a proven harness (such as a manual 328’s) separately and delete EWS?

One last thing, which ECU did you use?

[joeyb]

Everything from the E36 328i donor car, including the ECU. Sent it off to DanThe for EWS delete and map for M50 manifold.

[MyNameIsOllie]

Everything from the E36 328i donor car, including the ECU. Sent it off to DanThe for EWS delete and map for M50 manifold.

Great, thanks for the help!

[Brianmoooore]

Any of the looms can be used, but the E36 version places the various bits attached to it in places suited to installation in an E30. Cutting and extending of various wires is required if you use any of the others. All do able, but it's one more job to do.
If you have a complete donor car, I'd think twice about the EWS delete. This is an effective way to stop your car being driven away by thieves, and the necessary parts are easy to fit into an E30. All standard alarm/immobilisers fitted to E30s are laughingly easy to defeat.

[MyNameIsOllie]

Any of the looms can be used, but the E36 version places the various bits attached to it in places suited to installation in an E30. Cutting and extending of various wires is required if you use any of the others. All do able, but it's one more job to do.
If you have a complete donor car, I'd think twice about the EWS delete. This is an effective way to stop your car being driven away by thieves, and the necessary parts are easy to fit into an E30. All standard alarm/immobilisers fitted to E30s are laughingly easy to defeat.

Thanks for the knowledge, I’ll have to think about my options.

In terms of EWS, I was under the impression that it’s a huge headache to get working and since this is my first engine swap I wanted to keep it simple. However, if it is easy to do it might be worth considering. Do you have any useful links/info relating to the topic?

[Brianmoooore]

I'm sure there's info. in the wiki or M50/52 forum.
The EWS module and antenna just need simple connections to permanent and ignition switched 12 volts, and earth, then there's a single wire between the EWS module and the engine ECU. The ring antenna can be fitted to an E30 ignition switch/shroud with a bit of ingenuity, and the tiny transponder chip inside the E36 key will fit inside the torch type E30 key.
In the E36, the EWS also interrupted the signal to the starter motor from the key. This is also simple to do, but isn't really necessary, and from one point of view is unhelpful, since it alerts a potential thief that there is an immobiliser fitted, whereas if the starter still works, they might waste time cranking the engine and drawing attention to themselves.

[MyNameIsOllie]

I'm sure there's info. in the wiki or M50/52 forum.
The EWS module and antenna just need simple connections to permanent and ignition switched 12 volts, and earth, then there's a single wire between the EWS module and the engine ECU. The ring antenna can be fitted to an E30 ignition switch/shroud with a bit of ingenuity, and the tiny transponder chip inside the E36 key will fit inside the torch type E30 key.
In the E36, the EWS also interrupted the signal to the starter motor from the key. This is also simple to do, but isn't really necessary, and from one point of view is unhelpful, since it alerts a potential thief that there is an immobiliser fitted, whereas if the starter still works, they might waste time cranking the engine and drawing attention to themselves.

Ahh I'll look into it, thanks.

[Rinx]

I used an auto loom from an E36 and trimmed it down to fit. The auto part of the loom comes away quite easily and you can delete the traction control wiring and a few other bits as well. I can send you some pin out diagrams if you need them - you can use them to make sure you're not cutting anything you still need to run the engine!

[MyNameIsOllie]

I used an auto loom from an E36 and trimmed it down to fit. The auto part of the loom comes away quite easily and you can delete the traction control wiring and a few other bits as well. I can send you some pin out diagrams if you need them - you can use them to make sure you're not cutting anything you still need to run the engine!

Thanks so much man, I might have to take you up on that a little further down the line!

[MyNameIsOllie]

Still in the process of getting my donor car, going to daily it through the winter and wait until summer to get cracking. Figure I’m going to break the rest of it and make some money back with a bit of luck!

[Rinx]

Still in the process of getting my donor car, going to daily it through the winter and wait until summer to get cracking. Figure I’m going to break the rest of it and make some money back with a bit of luck!

Good plan. I done the same so give me a shout if you need any help!

[MyNameIsOllie]

Still in the process of getting my donor car, going to daily it through the winter and wait until summer to get cracking. Figure I’m going to break the rest of it and make some money back with a bit of luck!

Good plan. I done the same so give me a shout if you need any help!

Sweet, thanks man!

[joeyb]

I’d just add here that I used an E36 loom and it still needed trimming / adjusting to suite E30 standard ECU location. I can’t see how I could have used it ‘as is’ to be honest.

[MyNameIsOllie]

I’d just add here that I used an E36 loom and it still needed trimming / adjusting to suite E30 standard ECU location. I can’t see how I could have used it ‘as is’ to be honest.

So you had to cut individual wires and lengthen them?

[Brianmoooore]

I’d just add here that I used an E36 loom and it still needed trimming / adjusting to suite E30 standard ECU location. I can’t see how I could have used it ‘as is’ to be honest.

So you had to cut individual wires and lengthen them?

Extra length on several wires can be obtained simply by unwrapping the loom and taking up slack, but IIRC, the standard loom will just about do to get the ECU in the cabin, but not quite in the standard position.

[MyNameIsOllie]

I’d just add here that I used an E36 loom and it still needed trimming / adjusting to suite E30 standard ECU location. I can’t see how I could have used it ‘as is’ to be honest.

So you had to cut individual wires and lengthen them?

Extra length on several wires can be obtained simply by unwrapping the loom and taking up slack, but IIRC, the standard loom will just about do to get the ECU in the cabin, but not quite in the standard position.

Thanks for clearing that up