Morris Minor Owners Club

We just took the traveller out after a prolonged refit (replacement 948 engine and much welding and wood replacement) about 10 mile run into town and back (with a half hour break in the middle). Ran fine but when we got back I noticed that the top of the radiator and the heater tubes were hot (not so hot that I couldn't put my hand on them but hotter than you'd want to rest your arm on) bottom of the radiator was completely cold and no water had got past the rad cap and down the overflow tube. It was a warmish day and we trolled along not going over 50. A few minutes after we'd stopped, the bottom of the radiator gradually became warm. Car has no temperature gauge (these 948 heads don't have the tappings or it would have!)
So, it's got a new 82 degree thermostat (as far as I remember) does it sound like it's stuck shut, or is it likely on a run like that the engine hasn't got hot enough to open it? Instinct is to remove the thermostat and run without it to check for circulation (and check thermostat in pan of hot water) but before I do is it really just not getting that hot?

Sounds good to me. The thermostat must be opening for the top of the rad to get hot. If the bottom of the rad is cold then it is doing its job and it will warm up when the water is not being pumped around. If the rad was blocked the engine would feel really hot and you would probably be able to smell it.

Maybe try running it stationary for a while with the rad cap off - you may have air trapped in the system after such a big refit. Heater works ok?

Sounds perfect - what's the problem ?? Did the heater work ok ??

Thanks folks, wasn't sure there was a problem, just never actually felt such a complete polar difference between top and bottom (and thought I'd get a second opinion once I'd started mulling over it!) - when I've had cooling problems with cars in the past they've always been of the 'steam everywhere, way too hot to touch' type! And thinking about it, most of the problems have been with 'moderns' where the engine bay's so stuffed there's been no chance of getting a hand near the bottom of the rad anyway....

Does the heater work ok ?????

Jamie

Didn't check, will do next time we're out but since both the flow and return pipes were hot I can only think that it would have done quite happily.......

Always worth checking the heater - it's the first sign of trouble ahead if it stops blowing hot air!