MG MGB and MGB GT Tech Talk
My heater valve is leaking, so I've ordered on new one.
Just had a heat wave here in Perth, Western Australia, up to 42C, and now I have noticed my water flow has stopped, like a water pumpp failure or some blockage.
I have flushed the radiator and its fine
Could it just be my heater valve. Any way to check anything else?
Anyone have a reference for a diagram showing the water path to help me understand it all a bit better.
Thanks
Patrick
What is it that indicates to you that the water flow has stopped?
I had run the engine with the radiator top hose off and no water pumped thru.
That had beeb suggested on this forum previously I think...
Patrick
The thermostat might be stuck shut. Easy to check.
I'm assuming that the engine had reached operating temperature (about 87 degrees C)
If the engine was still warming up you would not expect flow out of the thermostat housing.
If the temperature reaches N and still no flow then after it has cooled I would suggest taking off the thermostat housing and removing the thermostat. At that point you might do a very very brief test run/turnover to see if the pump is pushing water out. Replace thermostat and gasket with new items if this is the case. If this is not the case, then it seems likely that your water pump will need to be replaced.
The heater valve itself cannot affect flow in the rest of the engine. It's simply a tap which allows or prevents water flowing through the heater matrix, nothing else.
In the Summer I bypass the heater on my car completely with a hose from the tap to the pipe on top of the valve cover.
I do this because even though there is no flow when the tap is closed the matrix is still open to water on the other side and eventually heat creeps into the matrix via that meaning that you get hot air in the car whether you want it or not.
I put the new heater valve in and it all worked fine. But now that seems odd, as Ernie pointed out, so maybe something else was the problem, who knows. I did flush the radiator in between, but it flowed straight away and nothing but water came out.
And thanks Peter, I had got up to temperature trying to test the water pump, so yes the thermostat was shut as it should be.
Patrick