Hello, new on here and am a novice so would apprecite some advice. Have an 06 Cooper Convertible and had no problems with it since I got it a year and a half ago. Noticed recently that the fan seems to come on with increasing regularity and after only even short journeys, though the temp guage shows normal level. After checking the expansion tank, I saw the coolant level was quite low so I added some water, set off and the temperature guage shot up to red within about three mins! It cooled down when I pulled over but overheated again after a few mins. The water is still in there, no sign of any obvious leak. Any ideas? Thanks!

The thermostat could need replacing.

You may well have an airlock after putting water in it.
Or as MINIAC says the thermostat is faulty, worst case is the head gasket has failed.
Has it pushed any water out of the header tank overflow at all?

You may well have an airlock after putting water in it.
Or as MINIAC says the thermostat is faulty, worst case is the head gasket has failed.
Has it pushed any water out of the header tank overflow at all?

Thanks for the replies. No, doesn't seem to have pushed any water out anywhere. I drove it again today for a few miles and this time the temp guage stayed where it should be. The fan did come on briefly and stayed on for about a minute after switching the engine off. Though the temp guauge was on normal, the car seemed very hot when I got out so I'm going to have to get it looked at, unless anyone has an obvious quick fix!

I have a 2009 Cooper S- overheated, losing coolant no signs of leak anywhere. Mini Garage replaced the water pump?

Got a garage looking at it now - one side of radiator is cool, other is hot so he's looking at the thermostat but thinks it might be the water pump. Sigh.

I have just had a new thermostat and housing for the same problem. Loosing coolant no leak. First the system was bled as they though there was an air lock. This didnt help.... they suggested it was either water pump or thermostat. There were signs that the water pump was working properly so had the thermostat replaced.... runs like a dream. Although still losing coolant but no overheating?? I am hoping it will be needing a few days to settle. I have an LPG system (previous owner fitted) this is also causing overheating so my additional problem could be the lpg.

I paid £150 for thermostat and housing, water pumps can be expensive I think?? Make sure you are not told it's the water pump just for extra money.... quiz them!!! Good luck xxx Apparantly thermostat is common in minis x

I have just had a new thermostat and housing for the same problem. Loosing coolant no leak. First the system was bled as they though there was an air lock. This didnt help.... they suggested it was either water pump or thermostat. There were signs that the water pump was working properly so had the thermostat replaced.... runs like a dream. Although still losing coolant but no overheating?? I am hoping it will be needing a few days to settle. I have an LPG system (previous owner fitted) this is also causing overheating so my additional problem could be the lpg.

I paid £150 for thermostat and housing, water pumps can be expensive I think?? Make sure you are not told it's the water pump just for extra money.... quiz them!!! Good luck xxx Apparantly thermostat is common in minis x

Thanks, that's useful to know - he did mutter something about £400 for a waterpump, but he's checking air block etc first...will report back.