Engine Over-Heating - Possible problems?

Hello,

Got a problem over the weekend, and i need to narrow down possibilties as to the problem, can you help?

Mini (cooper 2003) started behaving strangely, from around wednesday cooling fan would be on full blast when i stopped the car, then at the weekend, coming off of the motorway to idle at a set of lights, the temp gauge rocketed (Speed was cooling the engine down, hence the temp increase when i came to a hault). Checked coolant levels, expansion tank was empty - Topped it up between min and max - driving to work this morning, and same thing is happening, coolant levels now ok, but engine is over-heating quickly (again OK at speed due to forced ventilation cooling) other strange things, that point to a coolant issue....

I'm hoping for an airlock in the radiator
Although
It's probably a water pump issue!!!

Summary of symptoms:

Enginine Over-heating
Internal Heater blowing cold
Rushing water coming from the passenger side
Loss of coolant
No evidence of leaks
No evidence of cylinder head gasket being the issue (oil colour normal)

I'm going to ask my father in law to look at the car (Ford Mechanic of 35 years) but as he has not worked on a MINI before (besides a service), i'm wanting to pin point the fault first. If you can help, i would be very grateful.

Thanks
Gordon

Probably the thermostat and possibly the water pump

If it's ok at speed it's likely to be the themostat or air-lock. Do you have a scangauge or similar, to see accurate water temps?

No scangauge, but just found my coolant low again, and a wee damp patch below the car - Smells like antifreeze!!

Guess i have a leak somewhere!

Would that explain all the problems i've seen, like no internal heat, rushing water sound? Or is the problem still the water pump?

Looking on the bright side, i think i can rule out cylinder head gasket, oil is normal colour, phew!

Sounds like it's the water pump / Thermostat to me. I had the famous 'sound of rushing water' in my old One. It got taken back in under warranty and I think they replaced the Thermostat if I remember rightly.. I had to keep topping it up too 'til it was sorted.

Looked at the problem last night, turns out to be a very small leak in the radiator.

By god though, they haven't made it easy to access anything. I guess that they engineers had a nightmare trying to shoehorn all those components into such a small place, but after all it's a mini what was i expecting!!!!

It's sorted - good old Barr's Leak - No more radiator leak!

Well caught! (before it wrecked the cylinder head!) I had to replace that on my MCS, couldn't believe the cost of the bolts and gaskets. They alone made up 30-40% of the costs.

Do you trust Barr's leak long term? New radiator is £153 from Euro Car Parts. If your fix fails on a long journey you risk damaging a lot of parts?

maybe I'm just a chicken?