Morris Minor Owners Club

Hi we have a Morris Convertible but she is getting hot undet the collar.

I have replaced the cyclinder head, the top and botton hoses, the bypass hose and have now taken the theromsat out, but she is still getting to hot.

When running the car she is running about 60 (without theromstat in) as soon as I am static ie at traffic lights etc it only takes about 5mins for the temp to get to about 100 and then she struggles to run.

I have checked the tappets and the points, the water pump was replaced 2 years ago and i have removed it and checked it and it seems fine

I have blocked the radiator off from the car and filled with hot water and the slowly released the water and there is no cold spots so I think the raditor is fine

Does anyone have any other ideas I could try - she is suppose to be going to Goodwood for the weekend but I think at this rate she will have to stay at home

If it is 60 when running and heats up rapidly in traffic I would suspect the fan. Can you feel air being blown back on tickover? Is the fan standard? Not a mini one is it that will push the air towards the rad. If the fan is okay I would go for a recored radiator. A rad specialist should be able to tell you if it is blocked and either flush it or recore it.

Thanks the fan is a standard one - I did check the rad flushes through and tried it with hot water off the car and the slowly realeased the water and the rad got hot all the way through no cold spots, but I suppose that might not be a very technical way of checking, think I might borrow a raditor and see if that solves the problem - thanks for the help

I know of someone selling a rad at Hartney Wintney if that is close to you. Pm me if you want details.

If you're running without a thermostat you should replace it with a special 'sleeve', without it water doesn't circulate around the head water jacket properly.

60 is a bit too cold really, up around 80-90 would be better.
A service and general tune up would be a good starting point.
Make sure you include that tappets in the tune up.

You must not run without a thermostat. Is there any loss of water? Any pressure in the cooling system? Cracked block - or head? Possible blocked up water jacket - have you probed the drain plug on the block?

Forgot to mention it is a 1275 midget engine when we had the head off I checked that it was not warped and we have no loss of oil or water - havent tried the engine block drain - will have a look for that and try it when I get in from work tomorrow

thanks again for all your help

I think that you should get the rad properly checked over. If it is working properly it should be hot at the top and cool at the bottom. Flushing it through with a garden hose will not clear the capilleries, the water will just find the easiest way through

Ahh -1275 engine won't have a block drain. So - make sure it is the correct big blade 1275 water pump, and I would reverse flush the radiator. A rad swap with another car will at least tell you where the problem lies!

I don't want to put you off track as you seem fairly sure it is an overheating issue you have but Is the fuel pump ticking rapidly as if it getting too hot then it could be fuel vapourisation which isn't uncommon. Another tip would be to check the timing as if it is out then the engine will run hot.

If you do get stuck in heavy traffic turn off the engine and re-start when the traffic moves and leave some distance ahead of you so you can puul into the side of the road is you have a problem.

Hope you make it.

Switching the engine off for short periods will cause it to heat up even more as the fan and water pump will not be circulating and cooling the water. If you have a capillery type temp. gauge you will see the temperature rise when the engine is switched off. Modern cars have electric fans which cut in when the engine is switched off

You could temporarily fudge it with a leccy fan on a switch somewhere or wired into ign live? Zip tie it to the rad.

I'd guess timing too but going by your previous trouble shooting it'd be like telling granny to suck eggs.

My Minor had bad overheating problems earlier this year, after a lot of messing around it was found to be a partially blocked radiator. Remove the bottom hose, pour water in the top at a steady rate, check how quickly it runs out at the bottom of the rad. Also look into the top of the rad, what state are the tubes in that you can see.
A new rad solved the problem, very easy to fit.