Morris Minor Owners Club

Well, I did test the new thermostat, but couldn't see any noticeable movement in it!

Whereas, today I stuck the old one in a Pyrex jug of boiling water, and the central 'pillar' moved a mm or so, so I assume that still works.

My car has a Metro 1275cc head, so no bypass hose fitted.

If it stays shut - the heater should work really well - assuming water can get round the heater. If it's stuck open - then of course the engine will never heat up. Check for partially shut valve/kinked hose or blocked up heater rad...

One of my minors has an 82 fitted and the other has a 88 fitted. In the summer / hot day I noticed the 88 cars radiator was barely touchable and that wasn't with it sitting in traffic either. The 82 car on a hot day the radiator would be touchable / about right. I noticed this and the thermo degree after the head gasket blew on the 88 degree car after 4000 miles. I am going to change it to a 82 this summer as I don't really drive the car in winter and think alongside the higher temp of running on unleaded fuel the temp would be better a bit lower.

How many miles does it take for your heaters to work? I'm sure mine used to work within about 5 miles or so, but my regular journey is 7 miles and the heater currently doesn't seem to work within that distance.

My 1340 Mini - same engine really - would be demisting the screen within 1/4 Mile - and that on a really cold (but maybe not quite freezing) day. There must be a circulation problem through your heater matrix.

The 82 car would have heat through heater after 1/2 mile or so

Yes, I suspect my heater matrix may be in need of replacement. I recently back-flushed it using the garden hose, and water flowed freely in both directions through it. But maybe it's internally clagged up, so not much of the water is extending to parts it should...

Look to the hoses and the valve - do away with the valve - and just fit a stub on the head!

In the frost this morning I even thought about buying a log-burner.....

My Traveller doesn't have the heater valve, just the stub at the back of the head, and no bypass hose.

Tonight, as an experiment, I blanked off most of the radiator with a large 2 foot x 2 foot square of cardboard, then drove it 7 miles. The temperature gauge got up to half way, but no heat at all came out of the heater.

When I reached my destination, I popped the bonnet and felt the hoses; the heater ones were quite cold! Yet, the radiator hoses were warm as toast, as you'd expect, and the radiator was making some slight gurgling noises.

I'm mystified as to this heater problem! I'm suspecting the new 88 degree thermostat I fitted isn't working, as normally after this 7 mile journey, the heater hoses are warm.

So - where are the heater pipes connected? Are you getting a flow/return path? Look inside the car too - in case the hoses feeding the heater are 'kinked'. Other possibility is useless water pump - perhaps a 'small impeller' pump has been fitted? Or the impeller has corroded away...........

The hoses are connected to the lower thermostat outlet (Metro type) and the water pump, as per the photo:



I fitted a new water pump back in February 2013, which has a rotor at least as big as the old one that came off, so I don't think that's the problem. It made it through the hot summer and has covered 3,300 miles without any engine overheating, so that would indicate it works OK, I guess?

Perhaps the heater matrix is kippered after 43 years and 152,000 miles...

Normally the other heater pipe goes to the back of the head, is there a blanking plate there?

Mine has a late Metro 1300 head, and where the heater valve normally sits, it is either plugged or they haven't drilled the hole to let the water out at that end!

This why you have no circulation! Fit it to the back of the head - where it should be. The two little holes are already tapped 1/4" UNF - just run a drill bit through the middle hole - it's only thin. On the Metro set-up, is the thermostat above the 'take off' you have used - or below it?? It MUST be ABOVE!! If yours is below - you could try moving it - it will work wonders.......

This thread was started 8 years ago! Wonder where wibble is now? I think she had a van with paintwork that changed colour depending on the angle you viewed it. Expect she's settled down now, had kids, became sensible and forgot she ever had a minor! If you are out there reminiscing wibble, give us a sign.

I think Wibble was on fairly recently.....with a different problem.

Just checked Roy, December '12 was last post, so yes still about.

bmcecosse wrote:This why you have no circulation! Fit it to the back of the head - where it should be. The two little holes are already tapped 1/4" UNF - just run a drill bit through the middle hole - it's only thin. On the Metro set-up, is the thermostat above the 'take off' you have used - or below it?? It MUST be ABOVE!! If yours is below - you could try moving it - it will work wonders.......

OK, thanks. I shall try experimenting. I currently have the thermostat fitted to the head, i.e., below the heater take-off outlet.

Well no wonder you get no heat! It has to be ABOVE the take off point.....although I would still chuck the spacer piece away - and fit the hose on the rear of the head. But you will get a huge improvement by moving it up........