E28 ”M536”, getting it right.

[FiveThirtySix]

Hi,

Bought an already swaped E28. The price was decent enough for me to take a chance. Owned it for a couple months and so far I think it wasn’t a terrible idea of me to buy it. There’s a couple faults with it that hinders me from enjoying it in a way that both the car and me deserve so I figured that maybe starting a diary/thread about it could be helpful. I’m not that mechanically inclined but usually when I figure out what needs to be done I’m able to fix things myself. Sometimes I find it better to hand over to a mechanic but prefer to know what work needs to be done before I just hand it over and ask someone to “fix it”.

So I will go through the basics of the car, mods and known issues and take it from there. I plan on documenting the journey with photos and stuff here.

The car:

* Originally a 1987 M535ia
* S38B36 swap with 265 transmission
* XYZ Supersport coil over suspension
* Yellow Powerflex bushes everywhere
* E34 540 brakes front and back


Known issues:

* Wiring not great. According to a mechanic there’s nothing wrong with the swap and all the wiring in the engine bay is good. But the wiring under the dash is botched up. He described it to me as a bad job where the original E28 wiring under the dash meets with the new E34 wiring in the engine bay. Car electronics is where I’m the most clueless so I plan on sourcing an original E28 harness and have the mechanic replace it. Maybe someone here could offer advice in this, what sort of harness that would be and if it sounds reasonable that that would be the issue. All I know is that the car tends to light up the EML light in the dash and then kill the battery/shut down whenever I try using the turn signal.

* Sun roof not working, this is something I will fix myself.

* leaking front left coil over. Will either try to find a replacement shock or just live with it until I can afford to get new Bilstein B6 shocks and original M-tech springs.

* really bad stereo set up. Some aftermarket HU that only drives the front speakers. Will tackle this after I get the wiring under the dash working.

* Battery mounted in original location, I want to place it in the trunk like an M5 for the weight distribution and to be able to fit an air box in the front. This will also be for later after I get the car fully functional.

* The temp is always low. Don’t know if it’s just some problem with sensors, wiring or if its a bad thermostat. An issue that can get me nervous, and what really hinders me from daring to drive the car in any spirited way or dreaming of reving the car more than what I need.

That’s it I think. I drove it 700km home from where I bought it, and drove it to work a couple times after that but once it died on the highway after using turn signals and got parked in a really dangerous spot I’ve been hesitant and mostly had it sitting I the garage but I think it’s time to get working on it.

The goal is to have a car that can get beat on with respect and to have it less race car like and more like OEM+. Bushings will be replaced with rubber and long term I will go back to more period correct suspension.

I can’t seem to post pictures from my phone so will return with that when I get to my computer.

Hopefully this will be an enjoyable experience and I’ll someday soon have it to the point where I can just get out and drive it whenever I feel like it. It’s not going to be a daily but my main weekend fun car.

[Mike W.]

I see this is your first post, welcome to our group!

Your problems, while they might be intimidating if you don't have a lot of background in cars, don't sound all that bad. I don't think you want to go to an E28 fuel injection harness, you need to keep the S38 one, but obviously clean up what's there. Wiring for the most part isn't all that complicated on E28s, it's a matter of following it and the colors. I don't know what resources you have, but for US spec cars wiring diagrams can be found here, http://wedophones.com/BMWManualsLead.htm

It should be close, especially on the engine. Cleaning up bad wiring can be time consuming, but it's not that complicated, it's just following color codes. Mostly. Sometimes you have to try to figure out what they were trying to do and then do it right.

Running cold? I'd just change the thermostat for starters and see what happens, it might even be missing.

Good luck with it, a S38 is going to be a fun ride.

[Galahad]

can you upload a picture of where the two harnesses join?

[FiveThirtySix]

Thanks for your questions and suggestions. I’ve been busy at work and with life so haven’t gotten around the car but today I drove it from the garage to make room for my other car that needs some work. Been sitting for a while so it was a little hesitant to start but woke up to life and took me all the way home. Something is draining the battery so low voltage made the EML light and ABS light come in in the dash. Light for coolant and washer fluid as always was on.

Going to take pictures of wiring and of the car when it’s stopped raining.

[Mike W.]

The low coolant sensors are not the longest lived, it may just be the sensor. If you do replace it, be careful, often replacement sensors come with a nut without enough threads to really tighten correctly and you may need to use the one off your old sensor.

[FiveThirtySix]

https://flic.kr/p/2oRsWvq

https://flic.kr/p/2oRsWuo

https://flic.kr/p/2oRsWBY

https://flic.kr/p/2oRsnKn

https://flic.kr/p/2oRrmuT

Don’t quite grasp how to upload pictures yet but here’s links to photos of the wiring.. it seems like a mess, with stuff hanging down in the glove box.

[Mike W.]

Yeah, Flickr doesn't make it easy, though not as hard as Google. I had to dig in and find the web address for the image itself, not just the page. Don't have time to get them all up, but here's 3 of them.

[Galahad]

The wiring doesn't look completely horrifying, although vampire taps are usually not a good sign.
I'd be interested in seeing what the C101 connector on the side of the fuse box looks like - I just swapped an m50 from an e34 into my car so it should be somewhat similar.

[FiveThirtySix]

Just some random pics I took. Don’t know what’s the thing laying next to the fuse box?

Got new tires fitted 225/45 and 245/40 to make it sit nicer and look meaty. Really hated the “stanced” look it had before and ride quality improved dramatically.

[Galahad]

In pic #2 you're holding the low beam check relay

[FiveThirtySix]

As I’m working away on my 156 GTA that needs to be ready as my winter daily, doing the belt change and some rust prevention, I’ve just been enjoying the fiver.


Driving it to work.