The engine wiring harness on the R53 is a nightmare, who the hell thought it would be a good idea to put that many wires, connectors, and hoses in such a tight space? Anyway, after servicing the S/C today I find this broken connection plugging into the engine:



Broken connection with the male end still in there.



This is where the plug was on the engine. That's the grey hose going into the intake tube.

Can anyone identify this? Maybe a diagram of the engine wiring harness? I've searched forever on this. It's an octopus wiring nightmare! I also found another connection but can't find where it plugs, of course, my phone died before I was able to get a picture. I'll update tomorrow, that harness kicked my ***!

Thanks in advance guys!

 

It's the coolant temperature sensor (threads into head next to thermostat).

The bad news is you need a new sensor.

The good news is the plug on the harness side should be OK after you dig the broken piece out of it.

 

Yeah​, the harness side is fine, glad I don't have to replace that mess! I was able to pull the broken sensor's end out of the connection. Thanks for clearing that up!

 

Hmm, it appears all first gen MINI's​ use this sensor. So could I just steal the one out of my R50 and put it in the R53? Thing is the R50, thing is it has about a 140k miles on it but it had no problems besides tranny. I really want to get the R53 back up and running ASAP, but I'm having a hard time figuring out how to replace this even how to get it out of the R53? What would I use. A deep well socket won't go over because of the connection... And it looks like a box end wrench is a little tight in the area (very tight actually!). Any suggestions, I can't find much info on anyone ever changing these. I guess they don't really fail that much, just get broken, like in my case.

Thanks!

 

Double post; Mods please delete.

 

You'll have to remove the thermostat to be able to get a box wrench around the sensor.

Obviously, in either case, the coolant will have to be drained. I'd suggest that while you have the thermostat off, you may as well replace it as well - housing and all...

 

Oww dang, I'm one of those people that believes "Don't mess with it if it's not broken​"...

Oh well I guess at my mileage it wouldn't hurt, and if it absolutely has to be taken out to get that darn sensor out.

Okay, I've found the thermostat and housing, that was easy. But any recommendations as to the coolant temperature sensor? All I can really find is aftermarket eBay sensors. Not sure if a sensor is a sensor is a sensor, or if I'd be better off staying away from the cheaper aftermarket eBay version, that's all I've really come across.

Thanks man, you're a huge help. Super knowledgeable!