I have a 2006 MCS with a manual transmission. I have had the car since mid November 2012. It has almost 78K miles on it. I have experienced an intermittent problem twice. At slow speeds the temp gage would climb up until it was pegged high. Increasing engine speed would bring the temp down. I found the coolant was about a quart or so low so I topped it off with the proper coolant for the MINI. Several weeks later it occurred again. Again the coolant was low so I topped it off. I have not noticed any leaks. I had the oil changed at the dealer where I purchased the car just prior to the latest episode and they found no leaks as well. What should I be looking for? Does anyone have an idea what the problem might be?

THANKS

 

Sound like the low speed resistor went bad.

Check this thread out. https://www.northamericanmotoring.co...-solution.html

Check your expansion tanks for leaks and the cap to make sure when it is heating up it does not blow out.

 

No leaks and dropping coolant levels scare me. Common areas of coolant leaks are the thermostat, water pump and expansion pack but if no leaks are found you may have a bad head gasket. On the expansion tank leaks are hard to spot and the best way to see is if you have any greenish and white powdery substance on the heatshield under the expansion tank.

I would also check your fans operation, check the low speed fan resistor as it is a common item to fail but will not explain your loosing coolant.

Hope it's not the head gasket but if you have no leaks and are loosing coolant that may just be it. Check your oil, is it milky? Then a compression test would be my next step. Good luck and keep us posted!

 

I too thought of the head gasket but the oil is clear. Is there a way to test the expansion tank cap to see if it holds the correct pressure?

 

Is there any white residue on the metal heatshield under the tank? If not it may not be it but the tank is really easy to remove and check.

I would check pressure in the cooling system to check for leaks, if no leaks check compression.

 

Bleed the system too.