s50 sensor checks

[buster]

Hi guys.
I took the car out for a short blast.The engine oil got up to 80 deg C but i noticed the coolant temp gauge and the oil pressure light ( ON START UP) arent working.
Please could someone tell me the best way to diagnose the problems.
I suppose a continuity test from the sensor to the gauge and light would be a place to start but i cant remember where the coolant sensor is,or which pin to test on the cluster.
I know they are pins 4 and 5 on the c101 connector.

cheers
andy

[Brianmoooore]

4 is water temp and 5 is oil pressure on the C101 as you say.
Short these two to earth on the car side and see what happens. Oil pressure light should come on and temp gauge should go to full hot.
You realise that the M50 temp sensor has to be changed for an M20 one, and have used the brown/purple in the M50 loom, not the brown/yellow?

[buster]

welcome back brian ,havent seen you on here for a while.
The m50 sensor swap for m20,im not sure if i have to do the same for s50.I suppose only Ian can answer that one.
I will try the above checks though ,thanks,

andy

[Brianmoooore]

Really should read more carefully! Says S50, read M50.
Got a feeling that the S50 uses a combined ECU and gauge sender, so the M20 swap may not be possible. Still a thermistor of some kind though, so an interface should be possible simply enough.

[buster]

Maybe Ian will be able to shed some light on this when he sees this.
Im going outside now to test pins 4 and 5 to see if the dash responds

[ian332isport]

Hi Andy,

Only just spotted this one.

You need to fit the M20 gauge sender to get the temp gauge to work correctly. As Brian said, the S50 has a combined sensor, but right next to this sensor is a blanking plug that you can remove and pop the M20 sender in its place.

You then need to remove the brown/violet wire from the S50 4 pin sensor and move it across to the newly fitted M20 sender.

You don't need to change the oil pressure switch at all, so it's probably a wiring issue. Should be the brown/green wire on the E36 loom connecting to pin 5 of the C101.

Cheers,

Ian.

[buster]

thanks Ian.
Where is the coolant sender ? cant seem to find it

[ian332isport]

thanks Ian.
Where is the coolant sender ? cant seem to find it

Andy,

Have a look down between No1 & No2 intake runners. It's poking out towards the side of the car from an aluminium housing just under the first set of throttle bodies.

I've even got a photo



Ian.

[buster]

Nice one Ian,didnt even know it was there.Probably looked at it a thousand times !!
Just need to get a sender unit ordered up now.
Nice one on the picture,you've been asked this question before
BTW,took car out for a blast,i see what you mean by the short gearing,need a 3.64 now.

thanks

andy

[buster]

I checked the oil pressure sensor and its duff.Also,is this the correct part number for the water temp sender : 13 62 1 709 966 ? The etk lists 2 sensors but im not sure which one is the one for the ecu on the m20 engine and which one for the instrument cluster.

thanks

andy

[Beemer Redeemer]

I might be wrong, but i think .966 is for the temp display in the cluster. and .512 is for the ecu signal

But i would wait to get that confirmed before changing anything as im not 100% sure...

James

[ian332isport]

I checked the oil pressure sensor and its duff.Also,is this the correct part number for the water temp sender : 13 62 1 709 966 ? The etk lists 2 sensors but im not sure which one is the one for the ecu on the m20 engine and which one for the instrument cluster.

thanks

andy

Andy,

You need the 12 62 1 710 512 for the gauge. The 966 is for the ECU.

Cheers,

Ian.

[buster]

Ok thanks Ian,just phoned BMW back and ammended the order.
Wont be in till saturday ! that sucks.They used to be really quick.