The vehicle does not smoke and there is no mixture of water in the oil, but the engine is rather overheating faster now, less than 20 min with the AC on.

If the water pump is ok and you checked/changed the thermostat and it is not a head gasket (yet) then something is clogging the circuit. At that mileage you may have some of hoses plastic connectors starting to disintegrate and being conveyed through the cooling circuit. I had that problem on mine. If the hoses have not been changed yet at that mileage they need to.

also needless to say that you should not drive it until you find out what the problem is otherwise your next problem will be the head gasket

May be worth having the dealer diagnose it, that way it is their baby if it overheats again after they fix it as they do stand behind their work.

Is the high speed kicking on when the AC is on? If not you have a faulty fan switch which would cause the overheating

Hi Guys, looks like the engine head gasket is gone, I observed water vapour on the oil cap and the oil colour is milky around the oil cap. But there is no water contaminant in the oil sump, the dip stick is clean and oil texture okay. What could this mean, steam escaping to the top head cylinder but water not mixing with the oil. maybe starting to. Garrage is on holiday till thursday before I can take the car for repairs

I have actually stopped driving the car, embarrasing to stop here and there due to overheating. Using my Altima for now. The AC fan is working well. I will await the garrage to open then send the vehicle in for proper diagnostics and repair. Anyone heard of COSCHARIS MOTOR LTD. They are the authorised importer of BMW in Nigeria. Thats where I will be going for repairs but rather very expensive.

How did you solve the problem? Did changing the water pump help? Hope you're back on the road in the X5.

I'm curious as well, as this happened to me last night after leaving my truck at LaGuardia for four days. Drove it home to CT, and 1/2 it went to red, as I was arriving home, a red water pressure icon was flashing on and off and there was a distinct 'clicking' that came with the light. I was lucky to get it home. This morning, I filled the truck with coolant and 2L of oil and ran it for 20min and it seemed fine, albeit, the 'check engine soon' icon was on. Will take it to the garage ASAP, and the worst part is my wife needs to drive it tomorrow to take her mom to the airport with a lot of luggage :mad: