fried car! radiator, water pump, heater control problems

[badfelafel]

Hi! Finally picked up my moggie and subjected it to a horrible long journey on a very hot day... which took 9 hours to do 160 miles.

First stop - big overheat - blew out all its water and radiator empty! Found that the little heater control (the cable operated type just behind the rocker cover) (which has no cable and was wedged open with a cable tie) had water oozing out. Thought that was the problem and put some instant gasket on it.

But later on discovered that there was no water flowing past when we looked in the filled up radiator. Advised that its probably the water pump and radiator - and to replace them.

Does that sound right? Am just about to order a new heater control, radiator, thermostat and water pump.

Would be delighted if anyone has any experience/info!

[pskipper]

It's worth checking whether you need to order a new thermostat cover thingy at the same time, the one on my car was suffering from severe corrosion. Can't say whether the advice was right but replacing all those bits are fairly easy, just a little time consuming. Make sure you re-tighten the dynamo correctly when putting everything back together as you have to remove it to replace the water pump. Also do a search on the forum for best ways to remove a thermostat cover as they tend to get sealed on with limescale.

Good luck

Philip

[chickenjohn]

You could try flushing out the block and radiator first. Then re-fill with water and see how you go. Minors are vastly over cooled and I doubt its a faulty pump/ rad.

Other things to check- fanbelt tightened sufficiently?
Thermostat opening? if not then no water will flow to the rad.
BMC Ecosee may be close to you and be able to help ;)

[badfelafel]

Thanks for your (very quick) replies! By the way, who are BMC Ecossee?

[chickenjohn]

He's the online name of a Scottish member of this message board!Very helpful chap, and I know Scotland is a big place, but theres just an outside chance he may be near you!

[badfelafel]

Thanks! Will say hello to him - would be nice to meet a local minor fan!

[rayofleamington]

But later on discovered that there was no water flowing past when we looked in the filled up radiator. Advised that its probably the water pump and radiator - and to replace them.

Could easily be a failed (shut) thermostat. Failed water pump - not likely on a Minor however it is possible that the bblades rust away giving it almost no pumping action (a common problem if the car was run for long periods without antifreeze). I'vew seen this on a Minor and you still see some swirling in the top of the radiator.

Thermostat housing may well be severely corroded and the studs have a tendency to shear as well
If you are patient and don't need the car urgently you can see how it goes on dissassembly but if you need it back o the road in a rush, go for new hoses, new thermostat and housing and studs and nuts... and heater hoses if they are old. Then flush the heater and rad whilst you are at it.

[M25VAN]

But later on discovered that there was no water flowing past when we looked in the filled up radiator. Advised that its probably the water pump and radiator - and to replace them.

I had this and did all the usual flushing and replacing of pipes but unfortunately to no avail. To cut a long story short the problem went when I replaced the pump. When I did this I noticed the blades on the new pump protruded further than the old one. All back together and working fine. Can only assume that the old pump wasn't shifting enough because of the shorter blades.
Also if your worried about overheating you could fit one of the twin core radiators for about the same price.

[rayofleamington]

When I did this I noticed the blades on the new pump protruded further than the old one. All back together and working fine. Can only assume that the old pump wasn't shifting enough because of the shorter blades.

=

it is possible that the bblades rust away giving it almost no pumping action (a common problem if the car was run for long periods without antifreeze). I'vew seen this on a Minor and you still see some swirling in the top of the radiator.

?

[badfelafel]

Thanks for all your advice. I'll let you know what I do now! Perhaps flushing the radiator will be a good start, and replacing the thermostat if the housing will come off.

[Kevin]

And if you do take the pump off please dont forget to replace the little bypass hose with a fresh piece of heater hose the right size last time I did mine to my amazment it was full of silt just like the heater valve and after a flush through the heater worked a lot better as well, good luck.

[bmcecosse]

It's highly unlikely to be the water pump or the radiator. You don't really see that much flow when looking the rad top - certainly not till the thermostat opens. For now - fix any leaks (ie heater tap) and run the car up to temperature - keep on checking for leaks. The modern water pumps have larger/longer blade impellers - you need to be careful when fitting to older 'small bore' blocks - they sometimes foul on the inner casting - in which case grind away the blades, NOT the casting. Flush the rad by all means - but unless it's leaking it will be fine. Did the engine get so hot that it seized ?

[M25VAN]

When I did this I noticed the blades on the new pump protruded further than the old one. All back together and working fine. Can only assume that the old pump wasn't shifting enough because of the shorter blades.

=

it is possible that the bblades rust away giving it almost no pumping action (a common problem if the car was run for long periods without antifreeze). I'vew seen this on a Minor and you still see some swirling in the top of the radiator.

?

Nope, no corrosion on the blades at all, I always run with a good quality antifreeze.
The difference was that the blades on the new pump stuck out further from the pump body than the old did.
With the old pump in virtually no flow as the stat opened. With the new pump in noticable flow when the stat opened.
I've noticed that there are two types of pump for sale, with short and long impellors so I figure I had the short type originally.

[badfelafel]

Thanks - thats really helpful. The engine didnt seize ( I am DELIGHTED to say) and is still running fairly nicely but only gently until i get the overheating thing sorted! Cant help wondering if it was the weather. May get radiator pressure tested, and possibly fit temp gauge just in case.

[bmcecosse]

Temp gauge and oil pessure gauge are very useful. It's just been the tap leaking the water away - new tap = no leaks, it will be fine !

[rayofleamington]

Cant help wondering if it was the weather.

Unlikely - there must have been another fault.
I thrashed a Minor in the Sahara (40 degrees) and it only started boiling after the exhaust manifold had sheared (red hot fumes underbonnet) causing the points heel to melt making the timing go way off.

[badfelafel]

Always hopeful it will be fine Just ordered a bunch of stuff from Bull Motif, so it will be finer after!