Hi all , recently got a cooper 1.6 05 plate for the wife its started to boil over / bubble in expansion tank and I can see a steady flow of bubbles in the filler neck if I run it with the cap off thermostat housing , I'm starting to think the head gasket May of gone but there's no normal signs of this in oil or coolant the first stage fan wasn't coming on when we got it but I've fitted a new resistor and it's now working fine , just wondering if anyone has any ideas that are not the head gasket there's no visual water leaks and it doesn't loose any coolant but when the expansion tank boils it doesn't seem to flow back when the car cools down ? Thanks Paul

 

Hello Paul I have a Mini Cooper Sidewalk 2008. I've had a catalogue of problems including bubbling and overheating. I had a leaking cooling housant repair. I've still got the same problem. Somebody posted there's a second fan on a mini not working . Going to look into that. Really disappointed with this car it's cost me hundreds of pounds.

 

It's not uncommon for the coolant tank itself to have a leak. It's actually a very common compaints for the gen 1 MINI's. Can you take a picture and show us what it looks like? This is what ours looked like when it was leaking:



Are you sure you aren't losing any coolant? Is your level low? Coolant at that point in the engine bay can burn off before it ever makes its way to the ground. Be sure to inspect the tank for no visible flaws to rule it out as the problem.

Also, I'd suggest looking at the condition of your coolant tank cap. The seal can go bad in those. Make sure to not overfill the system as that will also cause it to boil over.

 

HI here ia pic I hope! The video I have you can see the Coolant bubbling up.It bubbles right up to the cap. Originally when I had the problem it used to blow the cap off. I can drive for miles but it's when Isit in traffic. This car has been a nightmare.