Well, that didn't take long. Its been about a week with my '14 jcw. I got a little obd2 gauge since all I have is a tach and openometer (I can barely type that without audibly groaning). Noticed that the coolant temp isn't getting above 180. No codes. Stuck thermostat, or is there more diagnosing to do?

 

Mine has been remapped to max out at 175. Are you sure yours hasn't had a new map --- mods?

 

No, I don't know if there have been any mods made. However, now I'm thinking it might be acting appropriately? 80 mile drive today, temp right at 180, briefly hit 185 when I laid on the throttle, then went right back. Got to the garage and let it idle, and sure enough the fan is cycling right at 180. That seems awfully cool, and everything I've read says it should be 200+. Anybody have any insight?

 

In the case of your car the 180F coolant temperature might be "normal" at a steady speed. At highway speed the engine is only being called upon to make around 40/45hp so it is not like it is working all that hard.

My 2018 JCW coolant temperature runs a bit above 180F in approx the 210F to 220F range gong down the freeway on my approx. 30 mile commute.

However, my other car a 2018 Hellcat on the freeway the coolant temperature drops to 190F or even a bit lower. However in town the coolant temperature can climb to 212F or even higher (the fans come on at 216F and shut off at 208F). (Oil temperature can go even higher to 231F is the highest I've seen it go. I have no idea what the oil temperature of my JCW is. No frickin gauges! Geesh.)

And with other cars I have observed in certainly cool weather as long as the engine is not being pushed hard the coolant temperature can be under 200F even under 190F. It was really quite an eye opener to see just how cool the coolant can be even though one is driving a 3000lb car (or 4400lb car in the case of my Hellcat) down the freeway -- on level ground -- at a constant speed of 65mph or even higher.

The JCW is I think a bit of an aberation but purposely so I believe in order to keep the engine at a pretty constant and higher temperature. The oil's working temperature is 212F so with the coolant hotter the oil is hotter and flows better and can shed any water better. With my Hellcat with the coolant down under 190F the oil temperature is likewise pretty low, too. Maybe just 5F higher.

 

Well, the problem isn't running too hot. Not sure why you'd intentionally want it run cool. It shouldn't have anything to do with the outside temp or (in general) how hard you're running the car. The temp should be whatever the dme wants it to be. If too cool, tstat either doesn't open or is closed by the dme. So. .. Can anyone confirm whether 180 is a normal operating temp for jcw?

 

I'm afraid I can't answer your question, nor does my Mini have the same engine (it's a 2010 N16 cooper).

However, I can confirm that the range it keeps coolant temperature within varies depending on speed and most likely additional factors like outside temperature and style of driving (i.e. throttle). At city speeds the range is from around 95 to 105 degrees Centigrade (203F to 221F). As speeds increase, the range is lowered. At and above 80 miles per hour (yes, I live in Germany) the usual range is 80 to 95 degrees C (176F to 203F).

Also, the more constant speed and load are, the "tighter" the range. And the harder the car is driven, the lower the temperature (within the above mentioned ranges).

Outside temperatures ranged between 5 degrees C and 25 C (41F to 77F) and I drove more than 4000 Kilometers (2500 miles) while observing engine temperatures. The thermostat housing was replaced in 2017 at a BMW dealer.

Edit: throttle and load added.