QuestionQUESTION: Hi I have problems with the coolingwater coming out in the hose at radiatorcap. I have been at a garage where they measured for CO,but nothingh found, suddenly while there,with cap off, water started coming out,mybe more then half a litre,then stopped again. I have changed radiatorcap,termostat,and asked everybody,but so far same problem. Any suggestions.
ANSWER: Hi Frank,
First test it to see if it is overheating or just over full.
Howard
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QUESTION: Hi Howard.
It's not overheating,the water just escape from overflow hose from time to time,and after a while you don't see it in the radiator.I suspected headgasket,but since no CO was discovered!!?? Very strange,is there somewhere it can suck air?? I just don't understand it.
Frank
AnswerYes, air is taken into the radiator every time the engine cools down after running. The radiator pressure cap allows air to escape when the coolant expands from heat and when the engine is shut down and it cools, a valve in the cap allows air to enter. If it were a sealed system as soon as the engine and coolant cooled, the outside air pressure would crush the hoses first and if that were not enough it would crush the radiator.
However. not much if any coolant should escape unless the radiator is over full. Many other cars have a extra tank to receive this expanded coolant and they don't get any coolant expelled unless it is overfilled which is most likely your case. Many MGs had expansion tanks.
If your car don't have an expansion tank you should consider installing one. It needs to be about a 2 qt container with the hose from the overflow pipe at the radiator cap neck run to the bottom of the new container and a vented cap on the container.
Howard
