my 1994 320i coolant hoses are bursting under what i call "undue pressure". Is it that my headgasket has failed and compression is getting in the cooling system.
The system was bled, i drove around on flat terrain for 10 minutes the temp guage went up  and then POW!! i realise the coolant connector to the heater core was broken. When i tried to refill the system it ran straight out on the floor.

Who are the possible suspects? Could a defective fan clutch cause it to overheat that rapidly?

It can be many thing. It can be radiator also.


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2008 BMW M5 BMW Parts Wheels

Pour some water in the coolant expansion tank and slide under the engine with a flashlight. You should not have a problem identifying where the leak is coming from. If the engine compartment is coated with coolant rinse it off beforehand. If needed, pump the upper and/or lower hoses by hand (while the expansion tank cap is off) in order to get fluids flowing. You will hear the water flowing throughout the system (kind of cool).

Whatever you do, DO NOT DRIVE THE VEHICLE! If you are losing coolant like this you run the risk of warping the head.....which will cost you mega bucks to fix. Many folks will tolerate a leak by continually topping off the expansion tank. This is not good and can actually add to or often be the cause of the problem; an expansion tank is just that, for expanding coolant (when hot). If you "eye-ball it" when filling and fill 'er up to the rim (with brim, sorry) the fluid expands when hot and, for the most part, has no where to go. Therefore something has to give and the weakest link in the system will blow. Make absolutely sure you are not overfilling the tank!!!

Questions:

"hoses are bursting"
??What hoses are bursting? (upper/ lower, breather, etc) Any hoses actually rupture or are they just bursting (or coming off) at the point of connection? Have you tried new clamps?

"under what i call "undue pressure"."
?? Can you elaborate on this? What is occurring and when? Are your hoses showing wear or bubbled anywhere?

"The system was bled"
?? Do you mean the coolant system was flushed, pressure tested and refilled? If so, did you do it yourself or have a tech do it? Basically, do you know what you are doing?

"the coolant connector to the heater core was broken. When i tried to refill the system it ran straight out on the floor. "
?? Can you describe broken? Is it a pin-hole leak, did it actually "pop" like a balloon? If the hose ruptured or became disconnected from the pump/ core then, obviously, any fluid would leak until fixed.


I hope you fix it and will help when or where I can. Caution: I was wrong once. BTW - if you have any digital pics that will help:)