Need some help troubleshooting some final cluster issues. S50 into e30 m3

[m3j0n]

I was hoping to get some help from the experienced 24v swap members in here to help me out. I have just completed a s50 swap (engine, tranny, wire harness) into my e30 m3. While the car isn't nearly as fast as I thought it would be in a straight line, it is absolute hooligan status on the street. Driving it today was realistically the most fun I've had in years, even though the car is not blistering fast. Drifts every corner effortlessly, sounds like a f1 car (open header - currently at the exhaust shop getting completed tomorrow), just straight nasty. Tops out pretty low, but more than arrestable speeds on the street. Going to put my 17" bbs rx on it tomorrow to see if that helps or hurts my gearing at all. All-in-all, the swap was an awesome little project and is, for the most part, complete with the exception of a few minor bugs that I would love to iron out.

I have used the stock e30 body harnesses, cluster, and Nando's harness adapter. Also, I am using the stock e30 m3 4.10 rear end. I am trying to troubleshoot some final issues, so hopefully someone can help me out.

4 current issues:

1. My first major concern is the Tach. It seems like the e30 cluster is reading about twice the actual engine RPM. Idle is like 1300RPM, when it should be around 700ish. It sure sounds like a regular 700prm. When driving the car, it quickly revs up (I know, I know 4.10), but goes clean past 8K rpm and then resets to zero with plenty of gear left. Is there anyway to get this to read accurately? It sucks driving around not knowing what RPM the motor is spinning at.

2. Coolant gauge is not reading coolant temp. I know it is getting power and receiving some type of input. When I start the car, the needle moves to just below the cold mark, but just sits there with no movement at all. How can I get the s50 coolant temp to display properly on the e30 cluster? The aftermarket fan that I wired in is working properly.

3. Oil temp gauge not reading. I know the s50 E36 m3 did not have an oil temp gauge in the cluster, but it would be really cool if I could get this to work. Has anyone gotten this to work accurately?

4. I still cannot get my turn signals to work, which is somewhat necessary to drive on the street.... (well, not for most people here in south florida). But I really want mine to work. Headlights hi and low, parking lights, and brake lights work, but cannot get the damn turn signals to work. Any idea where to start on this one?

Thank you!

[justin_l_]

I'm not sure on m3 clusters, but a regular e30 cluster you just need to swap the coding plug out with a 6cyl one. Its in the bottom right corner of the cluster when looking at the front. It just plugs in.

Did you use a brown top m20 coolant temp sensor in the s50 head?

Don't know on the oil temp gauge.

Turn signals are not swap related, I would suggest posting that in the electrical section for more support.

One more thing I would get rid of the 4.10 gears and go somewhere around 3.25. A 4.10 is awfully low for a street car, and with your new found power you should have no issue turning a taller set of gears.

[328ijunkie]

Ive gone through some lengths to get the S14 cluster to read a 6cyl signal AND a 8k tac. E28 M5 (or was it E34?) coding plug modified slightly works in most cases

brown coolant temp sensor

oil temp gauge you basically need to add a factory oil temp gauge somewhere (OFH preferred) and wire it to C101, shoulda had nando add the wiring for it. I do :P ;)

[nando]

I did add the wiring for the temp sensor. I'm pretty sure the 95 does have the sensor, it was even the same part # as the E30 M3. maybe it's not plugged in or there is some other problem?

for the turn signals, could the ground for the switch not be hooked up? it's on the steering column IIRC.

[328ijunkie]

Us cars never had oil temp, euro ones did. And the wiring diagrams still show it

[nando]

well isn't that misleading!

could add it to his harness with a separate connector. I'll see what I can come up with..

[328ijunkie]

Only issue with adding a connector is it's a code 2 and annoying to get a hold of

[nando]

it's not a 2-pin amp/bosch connector?

[328ijunkie]

Yes it is but its 'code 2' not the common 'code 1'
The keyway is offset.

[nando]

ah ok. I have a billion of those things, maybe I have one already.

[luckysnafu]

Us cars never had oil temp, euro ones did. And the wiring diagrams still show it

Z3M S52 cars have oil temp, and it's fantastic in my e30!

I figured you would know this :p

[m3j0n]

I'm not sure on m3 clusters, but a regular e30 cluster you just need to swap the coding plug out with a 6cyl one. Its in the bottom right corner of the cluster when looking at the front. It just plugs in.

Did you use a brown top m20 coolant temp sensor in the s50 head?

Don't know on the oil temp gauge.

Turn signals are not swap related, I would suggest posting that in the electrical section for more support.

One more thing I would get rid of the 4.10 gears and go somewhere around 3.25. A 4.10 is awfully low for a street car, and with your new found power you should have no issue turning a taller set of gears.

Thanks. Yes, the 4.10 is WAY too aggressive for the street, but I LOVE it. I'm sure it will get old, but not yet!!! definitely swapping to a longer gear down the road, but it sucks that I just installed the CSS rear diff bushing, a new m coupe finned diff cover, and new redline fluid....What E30 LSD options are there that I can swap in?

Ive gone through some lengths to get the S14 cluster to read a 6cyl signal AND a 8k tac. E28 M5 (or was it E34?) coding plug modified slightly works in most cases

brown coolant temp sensor

oil temp gauge you basically need to add a factory oil temp gauge somewhere (OFH preferred) and wire it to C101, shoulda had nando add the wiring for it. I do :P ;)

Brown coolant sensor is a single pin from a 1991 325i, right? Happen to have a part number for that one?

I was told by a friend that it has to be a e28 M5, a regular non-m 6cyl will not work properly on a e30 m3 cluster because of the redline. How does the coding plug have to be modified?

I did add the wiring for the temp sensor. I'm pretty sure the 95 does have the sensor, it was even the same part # as the E30 M3. maybe it's not plugged in or there is some other problem?

for the turn signals, could the ground for the switch not be hooked up? it's on the steering column IIRC.

will check the turn signals. Have any idea what wire colors they are, or if it could be a fuse that is out?

ah ok. I have a billion of those things, maybe I have one already.

Can we easily add one to my harness?

[Todd Black 88]

Grab a 3.25 LSD from an e28. The diff cover you have fits it, and you just need to reuse your diff output flanges.

[nando]

john I'll text you later. I think we can add it to your harness. Either that, or I can build another adapter and exchange the one you have. I'll need to dig through my boxes of wire harnesses to see if I can find one with the other key type, I'm sure I have one somewhere.

as far as the coding plug, you just have to remove it from the plastic housing, it plugs in the same. I'm not sure the E38 M5 coding plug is still available, but I think there's a euro E28 coding plug that will also work. maybe do a forum search on those terms, I'm sure I've seen that before here.

[m3j0n]

I just ordered E28 m5 coding plug. p/n 62111377664

I hope that was the right part!