Coolant Loss Followed By Heating Loss

[daro911]

2010 Cooper S 22k miles from new now losing 1.5L of water per 20 mile journey's and then the hot air goes cold which is the sign to top up again Absolutely no visible signs of where the water is going!

To date:
1st Visit new thermostat fitted was told car is definitely fixed
20 miles later problem is back again

2nd Visit 2nd water pump fitted was told car is fixed
60 miles later problem is back again!

3rd Visit now being told it has to be an air lock car with garage 3 days and 70 miles road testing etc was told car is definitely fixed

20 miles later problem is back again now waiting a loan car as garage is saying it has to be the head casket!

I have lost total faith in the R57 and am seriously considering all options as this cars lease is up end of March and my plan to run her another year has definitely been taken off the table

Anyone out in Mini world suffered similar issues to this one!

[daro911]

After 4 attempts one new thermostat one new water pump a complete bleeding of system the fault was finally found to be caused by a pin hole in a hose

Car is now back to normal at long last

[minioned2003]

We have the same problem on a 2003 mini one d. When my partner used to start car up there was a sound like something being primed. Now when she starts car there is no priming sound,the car is losing about 1.5litres of coolant on a 40 mile round trip with no sign of where coolant is going and the heater is blowing cold. Where is the thermostat found on a mini one d? The top hose goes straight into the engine block. Stuart.

[mab01uk]

R50 One 1.4d Waterpump - Thermostat:
RealOEM.com BMW R50 One 1.4d Waterpump - Thermostat

[minioned2003]

We've just been for a long drive in the mini one d,topped up coolant before.When we stopped we noticed coolant coming back out of expansion tank cap. Is the start up noise the coolant system pressurising?