Hi all.

I have a 2012 Clubman S that has been giving me overheating warning for several weeks now. I rarely drive the thing as I do not want to cause any damage to the motor, but and feeling rather hopeless because I can't seem to isolate the issue, and neither can several shops I have been to. Here's what's going on:

This started sometime in late February or early March. I was driving down the interstate, cruising happily, and the dash threw me a Yellow temp warning. Concerned, I began looking for the nearest exit so I could take a look. Not even 2 minutes later, I got the Red temp warning. I immediately parked where I could and stopped the engine. I didn't notice any steam, or anything abnormal under the hood. After letting it cool down. I started it back up, blasted the heater, and limped her home, driving like a grandma the entire time. This avoided any further temp warnings, but the temp still stayed rather high.

The next day, I began my quest to figure out what might be happening. I scoured this forum, as well as several others for several days, rarely driving the car in between. I found several users with similar problems, and noticed one of the most damning issues to be the thermostat. I ordered a new one, and had it installed that week.

This did not solve the issue, so I kept looking for answers.

I later noticed that my low speed fan had not been coming on, and seeing as that is apparently a huge issue with these mini's, I replaced the fan. This solved the fan issue, and it started working once the temp got moderately high, but it did NOT solve the overheating issue.

After more research and several days later, I decided to try the water pump. Ordered the part, replaced it- still overheating.

After doing all of these things, I finally accepted the idea that maybe the head gasket is blown. So I went down to the dreaded Autozone and got a test kit to check for exhaust in the coolant. I did the test, and it came back negative. I did this several times to make sure. I eventually took her to a shop down the road, explained everything, and they said they'd run another test, as well as a pressure test, check the head, etc, and get back to me. Lo and behold, they said everything seemed fine, and suggested replacing the radiator next, as maybe it was clogged. After quoting me about 800 to replace the rad, I took the car home and decided to do it myself. Still overheating.

I was feeling pretty lost at this point, so I took the mini to a European specialist shop and explained the issue. They said that they'd take a look, but weren't too sure what it could be after replacing all the things I had.

I let them keep the thing for several days, and checked in every so often, but in the end, they couldn't figure it out either. They said they ran their own pressure test, as well as another test for gasses in the coolant reservoir, but found nothing. They didn't even charge me for it since they couldn't figure it out.

This has all taken place throughout the last 3 months or so, and I have absolutely no idea what to do. I feel like I have read every single post on this entire forum, if not the entire internet, and I can't figure it out. Here's a rundown of her behavior:

Once I turn it on, the temp begins climbing slowly, as usual. Once it hits about 95-100C or so, the fan kicks in. This does NOT seem to lower the temperature, however, at least according to the C-TEMP monitor in the secret menu. The temp continues climbing, and once it hits about 110C, the high speed fan kicks on. But this ALSO doesn't seem to lower the temp. If I turn on the AC, the air blows cool, and I would ASSUME opens the tstat to get the water flowing, but the temp stays hot. It will climb all the way to 120C if I don't kill the motor. The ONLY way to keep it from getting that high is to blast the heater. If I drive around like a grandma and keep the heat maxed out, the temp hovers around 114C to 118C. This is the ONLY way I can drive this thing, and I only do this when have no other option, which is rare at this point. And with this Texas summer right around the corner, I'm feeling kinda screwed.

I'm pretty lost, and am very concerned on what to do. This is my only vehicle, and I need it for work, as I have been driving for delivery services like Uber Eats and Doordash for the past year thanks to Covid. I'm running low on savings, and need a solution. ANY help is GREATLY appreciated.

TLDR; r55 overheating, can't find solution ANYWHERE, including this forum, several others, and a few different mechanics. Have replaced tstat housing, water pump, radiator, and fan. Shops say they think head is fine. Temp will climb but will not drop. HELP

 

Thinking out loud here… The water pump is driven by the friction wheel assembly… Is it making contact with the water pump pulley and actually spinning the water pump? Is it possible the thermostat was bad, and then you reconnected the radiator hoses backwards, and it’s not flowing properly? Was there a check to make sure no air in the system?

 

The friction wheel IS contacting the pulley, yes. However, I'm not too certain how FAST it should be spinning. Personally, I would think it should be moving faster, but I can't seem to find any info confirming the speed. I'm no mechanic but it DOES seem a bit slow.

I don't think the hoses were reconnected improperly, but I'll double check. If that is somehow the issue and has been this whole time, I'm going to explode.

I believe one of the shops did a test for air in the system, yes. I've also loosened the bleed screw every so often just for my own sanity, and I'm not getting any air bubbles.

 

No codes?
Miles on car?
How many miles have you owned it?
This happen out of the blue? No possible previous repair/mod might be connected to the overheat problem?
Has the car spent it's entire life in Texas/SW?

Water pumps usually spin at crank speed or faster. Best guess is that the pump should be running around 110% (ish) of crank speed.
When a conventional serpentine drive slips, squealing results, the Mini's drive system may not do this.
An old and glazed belt and pump drive wheel could be factors.

Car cooling systems typically pass only a fraction of the coolant through the the radiator, the rest bypasses the radiator back to the engine.

If the pump's output is significantly short of the engine's cooling requirement,and therefore of the radiator's cooling capacity, then I would expect the radiator's outlet temp to be much lower than the inlet. The radiator's inlet temp should be very close to the engines indicated temp. A $20 IR thermometer would confirm this. Radiator outlets are typically at the bottom, inlets toward or at the top.

 

Could the coolant temperature sensor be at fault?

 

No codes.
About 125k.
About 75k of those are mine.
Yes, out of the blue. No previous mods/repairs, at least that I'm aware of. I've had the car for about 6 years at this point.
She's a Texan through and through.

I don't hear any squealing, or any odd noises for that matter. The water pump pulley was showing its age, so that was replaced with the pump. The belt looked fine, but I guess it wouldn't hurt to replace that as well.

I'll grab an IR thermometer next chance I get!

 

I do not believe so. I thought this after I replaced the thermostat, figuring that perhaps the new sensor that came with the thermostat could be DOA, so I replaced the sensor, but the problem still persists. :(