We have 2 MINI's. A 2013 R56 JCW and a 2011 R55 MCS. Both have the JCW temp and relative torque gauges in them. The R55 coolant temp runs pretty much steady state @ 105C, except when climbing a steep grade or going down a gear to pass, then it drops to 90C like the high speed fan comes on, then goes off when load on engine decreases, and temp goes back to 105C.

The JCW warms up to about 93C then drops back to 90C steady state, or going up hill or accelerating. Never goes to 95C even in hot desert weather. Does the JCW just have the high speed fan on all the time? It very seldom comes on when I park and shut off. The MCS fan comes on, and stays on longer more than the JCW. Oh, also no A/C on in either car.

Does anyone know? Where are you MINIwhisperer?

 

The minis have a 2 stage thermostat, at 85C and 105C.

Normal driving in my 2008 JCW the thermostat sits at 105C. However, if you drive aggressively, hard acceleration etc then the second stage opens and the temperature drops. However, it rarely reaches 85C, usually around 90C. The opening of the second stage is ECU controlled.

My 2013 GPII never uses the the first stage, the 85C loop is open permanently no matter what. Maybe the 2013 JCW is the same?

Both cars the fan will come on if there is no airflow through the radiator (ie stopped or very slow traffic) and the temp goes over 105C

 

My thermostat broke a while back. I remember the fan kicks in at 115 C on high speed.

 

Okay. What you describe on your 2008 JCW is exactly what my wife's R55 does after they put in a new thermostat friday. I took it in because the temp never got above 60C, and gave a warning light.

However, I think what is happening with the 2013 JCW and the GP2 is that the DME, or ECU as you call it doesn't ever set the thermostat to 105 C, and only uses the 85C opening temp. That is what I see on my gauge. It warms to about 91 or 92 then falls back to 89 to 91 steady state. Even in the desert and 100+ F. That makes sense to me as the 2013 JCW and the GP2 actually share the same engine. Because of the higher boost in those engines and the possibility of detonation under power the ECU wants the engine to stay cooler. Also why they lowered the compression ratio from 10.5 to 10 because of the added boost.

Any thoughts on this out there?