Overheating!

[dannymac]

Hi, i hope that this problem sounds familiar to some body. Here goes, i travel up north quite a lot and some times like to take my Morris minor. Goes like a dream since i have had it (even taken it to the south of France this summer).
Anyway i got as far as Oxford this weekend and had to pull over because steam was coming out the bonnet. Lifted the bonnet and slowly took off the radiator cap and you have guessed no water. After i left it to cool off i checked to make sure there was no water in the oil and there was no sign of any. I filled the radiator up again and went to the next services and it needed topping up again.
Thermostat i thought next but i could not get the housing off because it was seized solid. To get me home i kept filling it up and with the heater on and with my hand in front of it i could tell if it was getting to hot or not. About 25 minutes and i had to pull over and let it cool.
Got home and the next morning went about getting the thermostat out. Had to smash the housing off in the end but luckily i have another car on Mums path so nicked the one off that.
Left the thermostat out and went on a two hour drive and it was fine so thought i had cracked it. On the way back it started doing it again. There was still no thermostat in it so its not that, there are no leaks on the cooling system, no water is getting in the oil, no oil is getting in the water and there are no bubbles coming out the radiator.
If i stayed at 55mph on the way back it was OK with the heater on and the windows down as soon as i went over that it started to get too hot.
I am either going to change the water pump or do the head gasket but wanted to know if anyone had had this before, sorry its a long one but wanted to make sure i got everything in. I'm hoping its the water pump could it be that at low speeds its OK and then when it speeds up its no good?
Anyway hope a few people read all this and let me know,
Thanks, Danny.

[Packedup]

If you're not leaking water then you're losing it either through the rad cap or the headgasket (or worse, cracked head!).

Could be that it's only being lost through the engine when it's hot, and straight into the combustion chamber so no mixing with the oil.

The pump might not be pumping all that efficiently, but I'd still expect to either see water leaking from it or blowing out the rad if that's the case.

[minor_hickup]

I had the same thing, it was fine most of the time until you ran it for a long time fairly fast. I tried flushing it, changing the thermostat and water pump and it was a blocked up radiator. Even though I flushed it clean several times when i replaced it made the world of differecne.

[rayofleamington]

unfortunately this could be a couple of different things - blocked radiator or faulty waterpump as mentioned, also headgasket.
It could even be a big problem with the timing (eg 20 degrees retarded) - this is an easy mistake to make if the distributor drive is set in the wrong position as you can easily set the timing to the points closing instead of opening.

[bmcecosse]

Look carefully for any leaks - could be bypass hose - or as above - damaged pump although this would be most unusual. If nothing else found - then off with it's head!

[dannymac]

Thanks for all the advice. Think i will take the head off this weekend and let you all know how i get on. Dont think i will bother with the water pump as they are never suposed to go. Thanks again.
Danny

[bmcecosse]

Indeed never 'supposed' to go - but neither are timing chains and one was reported last week! It's only 4 bolts - and a new one - which has bigger impeller these days - is only £15, indeed I only payed £5 (brand spanking new) at autojumble 2 weeks ago!!

[chrisd87]

Dont think i will bother with the water pump as they are never suposed to go

I had one go on me. Check the bearings by trying to wiggle the fan around - if you can feel a reasonable amount of play, then that may be your problem as the worn bearings can allow water to escape (as happened in my case).

[paulk]

I changed the pump on mine last easter. It didn't leak but rumbled like an elephant with wind.

Also don't forget the little water pipe thats on top of the pump as it is easy with the head or pump off but a bugger to get at later.

[chickenjohn]

It could be a fine pin-hole leak in one of the hoses causing the water to dissapear. Check the hoses very carefully. Other than that - the above ideas as suggested on this thread.

[rayofleamington]

Dont think i will bother with the water pump as they are never suposed to go

at 40+ years old, anthing can fail. They can leak or the bades have rusted away so they hardly pump at all. I've seen both problems on Minors, but yes - in terms of probability it may be less common than a head gasket failure.

[dannymac]

I should have swapped the pump over off my other minor while i was at home but its too late now. Before i dive in head first and take the head off im going to drive to my mates tomorrow and see if he has a pump i can borrow and while im there swap the rad and take it from there.
Cheers guys!

[Kevin]

Dont forget the heater valve if you have the later type with the push-pull control as they can leak and if it runs down the rear of the engine its often missed, have a good look round all the culprit areas and see if there is a dried water trail anywhere.

[dannymac]

That was one of the first places i looked, there are defenantly no leaks anywhere waterwise. The oil ones i know about, by the way does anyone have a minor with no oil leaks whatsoever, i mean none not even a trickle?

[RogerRust]

at 40+ years old, anthing can fail. .

I'm still running on all cylinders and on the original engine and punp.

[Kevin]

I'm still running on all cylinders and on the original engine and punp.

So am I but I am only single cylinder