Irish Mini Owners Club

After a period of storage i have started using my mini Cooper S Again 00 G 23


After a short while the expansion tank starts bubbling .

i have checked the following
thermostat replaced
new coolant
Head Gasket oil clear no evidence of a damaged or blown gasket
fan cutting it at temperature but not colling it down sufficiently



any ideas what next ?


Terry

As the car has been sitting up the first thing to check is that the stat is opening.
MPi engines run a normal temperature around 100 deg. C so it is important that the cooling system holds pressure as water boils at a higher temperature under pressure. Is there any steam coming out. MPi expansion bottles are known to crack where the hoses join the tank.

Terry,

What thermostat are you using? Mpi's run hotter than carb Minis. I had overheating problems with my old 98 mpi but it was a common problem with a sensor which was activating the fan. There was a factory upgrade which cured it. The other possibility is that your 20-year-old rad has silted up.

Woody beat me to it.

The other known issue is the quality of the expansion tank tops. As Woody says, the system needs to be pressurised to work properly.

Thanks guys


rad checked and ok
upgraded stat and its working
no evidence of blown gasket

the hunt goes on .

hope ye are all well during these terrible times
Terry

Try replacing the coolant header tank cap, I replaced mine with one from a 2006 Mini Cooper S.

Instantly stopped any heating issues on my 2000 Sportspack

thanks guys im taking a few days off this week and will get stuck in to it

Check the cooling fan speed. It may be cutting in OK but may not be turning fast enough. I had this problem with one turned out to be bad earth to fan. 9

I had a problem with overheating on my 2000 Cooper Sport, the coolant was flowing through the rad but not being cooled , a new rad solved the problem but I tried everything else before replacing the rad.