Bmw overheating problem overheats very quick even with thermostat removed?

From what i have read it could be the head gasket but im not entirely sure as there are not many if any of the tell tale signs ie. there is only a little smoke from the exhaust (and only when engine first starts), no white gunky stuff under oil cap and the coolant is the right colour. I have changed the thermostat, and have taken it oyt completely now and also changed the radiator and oil. The only thing left from what i can gather is the water pump but have absolutely no idea where i can find this on the car or if i should even attempt it being a total novice.I had the car garage take the ecu from my girlfriends car and put it in mine before this started happening but im not sure if that could be the problem.Sometimes it seems to work but lately its always happening so i is possible air pocket but i dont know how to fix it If anyone could please help me as to what else i could try and where i can find the water pump i would be very gratefull.

cheers

danBmw overheating problem overheats very quick even with thermostat removed?
Water pumps almost never fail in that way for one thing. The first thing to check is whether or not the fan is working. If the fan is mechanical (attached to the engine) it should turn slowly when the engine is cold and fast when it gets hot. If electrical fan, turn A/C on, if fan turns on then you know the fan works, if it doesnt, you have an inoperative fan. Secondly, does the gauge just read hot or is the engine actually overheating? You need a good mechanic as this is the most common cause of blown engines. And yes the new ECU could have caused this problem, in fact that is the most likely cause. (wiring not hooked up right)Bmw overheating problem overheats very quick even with thermostat removed?
Don't know where the water pump on a BMW is, but it will have a pulley and a belt attatched to it. Check and see if any coolant is leaking around it, it should have a %26quot;weep%26quot; hole, also check to see if the pulley seems stable.



To bleed the system for air, start the car, take off the radiator cap, and watch for circulation, if your pump is working, the air will eventualy rise to the top, and you can add more coolant.

If there is no circulation, then the pump is probably bad.

give me an advice

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