Cooling problem

[peterrc]

Hi Guys, My Stag TV8 MOD has been driving well all year. Two weeks ago after towing the caravan I thought that it was slightly higher than usual and topped up the water level. Expansion bottle half full with top on and filled to overflowing at radiator fill point.
Yesterday after leaving home I put on the heater and nothing happened for about 5 miles. The Temp was creeping up and about 2 to 3 mm from the red. Suddenly the windows misted and we had heat. It was all right, just below half way, for the rest of the 70 mile journey. When I checked it on arrival, after it had cooled down, the expansion bottle was full.
It did exactly the same on the way home despite having the 13" kenlow on and the heater on max. Rather than risk it overheating I left it like that and had a very warm left leg by the time I got home. I suspect the thermostat is sticking but would appreciate any other thoughts from the 'forum'.
Peter, Cupar

[pcoleman]

cant say for sure but sounds like an air lock some where in the cooling/heater system.

peter.c

[therat04]

Hi Guys, My Stag TV8 MOD has been driving well all year. Two weeks ago after towing the caravan I thought that it was slightly higher than usual and topped up the water level. Expansion bottle half full with top on and filled to overflowing at radiator fill point.
Yesterday after leaving home I put on the heater and nothing happened for about 5 miles. The Temp was creeping up and about 2 to 3 mm from the red. Suddenly the windows misted and we had heat. It was all right, just below half way, for the rest of the 70 mile journey. When I checked it on arrival, after it had cooled down, the expansion bottle was full.
It did exactly the same on the way home despite having the 13" kenlow on and the heater on max. Rather than risk it overheating I left it like that and had a very warm left leg by the time I got home. I suspect the thermostat is sticking but would appreciate any other thoughts from the 'forum'.
Peter, Cupar

Hello Peter you did not say how low your water level got, if it was low enough to effect the temp then when you refilled it did you make sure the heater control was set to hot, because if not you can create an airlock....Steve

[peterrc]

Hi Peter & Steve, thank you for your replies. To answer your questions the water level was at the top of the radiator & the heater valve was open. I have checked the thermostat and it is opening in the early 80's. There is no temp stamped on it only 'motorad'. I will replace it anyway and bleed the system as per forum guidelines. I had planned to fit a Mercedes header tank over the winter but might bring that forward.

Many thanks
Peter, Cupar