I am a fool (with audiance)

[Maverick]

Thought I'd run the beast for a little while before driving home from work this morning, and with this cold weather she builds up pressure quicker than she gets warm (she doesn't warm up well when stationary). Got held up with a delivery and left her running longer than normal, so the pressures lifted the cap enougth to put water into the expansion tank and start a little drip. Now me I panicks check guage 1/4 warm switch off, open bonnet check top pipe - cold. Open rad cap. Boy do these things work pressurised or what, cap ended other end of car park, and I ended covered in coolant. Refilled with water (must now check dilution level) replaced cap (when found) and drove home no problems.

Now the best time to do this is SHIFT CHANGE, maximum audiance possible.

The question possed was is there something wrong with the car, answer, no the problems with the owner..

[Morr]

.............Open rad cap. Boy do these things work pressurised or what, cap ended other end of car park, and I ended covered in coolant..........

Very lucky you just got wet, Friend of mine lost a great deal of the skin from his forearm thru opening a rad cap when the engine was hot (a mechanic too, should of known better but drunk at the time). He spent weeks getting daily dressing changes etc. The water in the cooling system is under pressure and often well over 120 degrees Celsius, thats a lot hotter than your kettle can make it and several times hotter than needed to burn, it will lift flesh into giant blisters instantly.

[Donk_UK]

But did you let the engine cool down befor eyou replaced the water??? head crackage if not

[da SLUG man]

i can't see that you should get much pressure from a cold engine... the pump only circulates the water around, the pressure comes from the water getting hot and expanding... it will get to a higher temperature before boiling, that's why it usually boils when you take the pressure cap off and sprays up your face!

[Maverick]

The way I understood it was that the stat wouldn't let the water circulate until it reached a certain temperature, which would mean the system would be under pressure from the pump (I could be way off due to NO mechanical knowledge). The engine hadn't got warm at that point as mine doesn't seem to warm up when idleing (I think this has something to do with the fan running more at low revs, cause if I'm moving she reaches temperature within a mile). The water was definately cool (but not as cold as the air). I definately looked like (and acted like) a pratt.
And most of all I'm very paronid about the head at the moment, I'm off to Scotland at the end of the month and although the stat and cap were changed last November, I may just change them again using proper Toyota ones.

[da SLUG man]

the stat opens to allow water to reach the radiator... so until then it just circulates around the engine block until it's up to temperature... the stat will open and close a few times as the cold water from the rad part of the system cools it... after a while it will stay open as all the water is up to temperature...


the fan wont be turning properly when it's cold because it's viscous and works on a type of clutch that locks when hot. (although they turn when v.cold too!. that's the whirring you'll hear when pulling away first thing in the morning)

[Guest]

The way I understood it was that the stat wouldn't let the water circulate until it reached a certain temperature, which would mean the system would be under pressure from the pump (I could be way off due to NO mechanical knowledge). The engine hadn't got warm at that point as mine doesn't seem to warm up when idleing (I think this has something to do with the fan running more at low revs, cause if I'm moving she reaches temperature within a mile). The water was definately cool (but not as cold as the air). I definately looked like (and acted like) a pratt.
And most of all I'm very paronid about the head at the moment, I'm off to Scotland at the end of the month and although the stat and cap were changed last November, I may just change them again using proper Toyota ones.

The pump won't pressurise the system, it would only do this if it was being fed extra from behind with nowhere to go. All that happens is that the pump turns and the water doesn't circulate. The only thing that will pressurise the coolant is heat or combustion chamber.

Best way to do a quick check - run the engine from cold with the rad cap off, if it pumps out water pretty much straight away then there is a combustion leak into the cooling system, head or head gasket (most likely head) is leaking.

If it pumped enough pressure to do that to the cap and the water didn't scald you then I would definately suspect a cracked head.

[Maverick]

Andy

My system has always pushed the water over the rad cap, so now I'm worried as I've done nearly 20,000 miles since getting it (1st UK owner).
I think it's now time to start saving for a new head, and get it changed.
She is still running sweet with no oil/water mix loss of power or water, but with your discription I think I'll play safe and have the head changed.

Duane