Morris Minor Owners Club

OK guys, this is of academic interest only as it happened to me about 35 years and, for some reason, it has popped into my mind again recently.
Driving down the M5 in a traveller, I suddenly noticed brown water squirting up under the bonnet handle and stopped to find all the obvious signs of over-heating. I let the engine cool and nipped down into a conveniently close valley for some stream water, topped up and carried on my way. There were never any subsequent over-heating problems and the question is - why did it happen only the once?

Thermostat stuck in closed position?

Coolant level got so low that it then overheated?

You stopped thrashing it unmercilessly?

Weather was never as hot again?

You kept the heater on after that episode?

Might think of a few more possibilities if I really had to, but I won’t.

Aliens.

An enchanted stream is a nice thought

Thanks for the replies. I doubt the thermostat could have stuck on as I was already 70 miles into my journey and all had been well up until then, so it must have been open.
Coolant level low is possible, but not sure why, as it was OK subsequently, so there can't have been any leaks.
I don't think I've ever thrashed a Minor unmercilessly!
Aliens? Unlikely.
Enchanted stream? Again unlikely, although a charming possibility!
The water issuing forth was very rusty - I wonder if some crud had blocked up the cooling system which was then blown out when the temperature rose and opened the rad cap?

The water issuing forth was very rusty - I wonder if some crud had blocked up the cooling system which was then blown out when the temperature rose and opened the rad cap?

I recon it was that. Something similar happened to me in a Triumph Herald many moons ago.

Bit to early to blame it on Brexit, I suppose?

A random page from a newspaper or plastic bag blown over the radiator grille that blew away again once you'd stopped, possibly.

I doubt the thermostat could have stuck on as I was already 70 miles into my journey and all had been well up until then, so it must have been open.

Exactly what I thought when it happened to me. A P100 with a well loaded trailer and about 45 miles from home. No problem on outward journey (empty) of 50 miles and none for ten miles, or so, on the way back, heavily loaded.

First thing I noticed was the temperature gauge rising into the red, but it did not come down, even on about a mile of light engine load - a steady slightly down hill run. First thought it was too much load for the truck on the long drag up hill, but had to stop when it failed to recover as I thought the fan was not working. Allowed to cool and refilled with water and no problem on the rest of the run. A few days later I was told someone else had the same problem on a local run ( without a tailer) and they found the thermostat was stuck. Changed at that point.

That was the only time with a thermostat syuck closed - I have had a couple that stuck in the fully open position, over the years.

I don't disbelieve your anecdote, but still not convinced that a vehicle could run so many miles (over 70 in my case) without overheating trouble if the thermostat was stuck shut. Even if that was the case, I can't see how a thermostat would stick shut, then open itself and work perfectly for several years.........until I had to scrap it
The suggestion from 'panky' is a bit of a long shot but it could happen!
With 'Owlsman' having a similar experience, I'm inclined to go for the temporary blockage theory. But we'll never know.....
PS It can't be blamed on Brexit, as it happened in the mid-1980's!

SteveClem wrote: ↑Tue Jan 14, 2020 1:52 pm An enchanted stream is a nice thought

As long as there isn’t a naked old hag rising from it with a sword in hand shouting for someone called Arthur....

A similar thing happened to me about ten years ago. It was winter and I was just a few miles from home when I was held up in a queue of traffic. A huge plume of steam bellowed out from under the bonnet. "Oh dear" I thought. "Looks like I will have to do some work tomorrow." I got home and checked under the bonnet. All was well so I left things as they were. The engine has run fine ever since.

King Kenny wrote: ↑Mon Jan 20, 2020 12:02 pm A similar thing happened to me about ten years ago. It was winter and I was just a few miles from home when I was held up in a queue of traffic. A huge plume of steam bellowed out from under the bonnet. "Oh dear" I thought. "Looks like I will have to do some work tomorrow." I got home and checked under the bonnet. All was well so I left things as they were. The engine has run fine ever since.

The only time it's ever happened to me was my old pickup out in Nevada back in 2008.
Luckily we were only a mile or so from home after being out on dirt roads in the desert most of the day .... Split top hose.

'split top hose'- yes, but that's not a mystery overheating!
Interesting though that at least three of us had cars that seemed to fix themselves - how cool is that!!?

myoldjalopy wrote: ↑Mon Jan 20, 2020 8:47 pm 'split top hose'- yes, but that's not a mystery overheating!
Interesting though that at least three of us had cars that seemed to fix themselves - how cool is that!!?

But it was a mystery until I found the small split (only about 1/2"long on the underside).

I do think a lot of such 'mystery' bouts of steam are caused by over filled radiators with sticky pressure reliefs that suddenly open as the pressure increases rather than creeping open as the pressure gets to the relief point.
Hence a woosh of pressure release before closing again.

Chappers wrote: ↑Sun Jan 19, 2020 6:53 pm

SteveClem wrote: ↑Tue Jan 14, 2020 1:52 pm An enchanted stream is a nice thought

As long as there isn’t a naked old hag rising from it with a sword in hand shouting for someone called Arthur....

Weell..... I was thinking more ambient birdsong, a carpet of flowers under some magic trees.......and talking animals.