1998 MPI overheating problem?

Hi,

I've got a "Rover Mini Cooper MPI 1998", In which I've had an overheating problem the last few weeks. Basically, the electric fan does not come on in time to cool the engine down? Hence the Mini overheating, and dumping all it's water. So I've eliminated some problems. I've changed the thermostat, the sender unit, the water pump and flushed the system out. Yet, this does not cure the problem. Correct me if I'm wrong but, the only thing I could think to do would be the head gasket? Might be blocked etc..? Can anyone help and tell me why, if it was to be the head gasket that, that would be the problem?? Or, does any know what else the problem could be?

Regards,
Flea

hey,
so you've replaced the thermostat, and i assume by sender unit you mean the coolant temperature sensor? you say the fan doesnt kick in soon enough, this would be purely related to the coolant system. Therefore if the engine is overheating due to running lean or having a blown head gasket, it wouldn't delay when the fan kicks in. if this was the case, it would overheat even if the fan was working correctly. Have you checked the radiator, it could be partially blocked meaning, the part of the radiator where the temperature sensor is located is not getting a flow of coolant to it. therefore it could be staying cool whilst the engine is hot thus not turing the fan on letting it overheat.

however if the fan is working correctly, a blown head gasket could cause your engine to overheat yes, are there any other symptoms? oil in the water? "mayonaise" in the oil? using coolant?

hope this makes sense and helps

is the fan actually coming on?