Club 80-90 Forums

1983 1.9cc Watercooled.

Whilst driving along doing about 45 mph the road behind me was suddenly filled with white smoke/steam. I then reaslised quite quickly that it was me! Obviously straight into neutral, turned egine off and coasted to a halt. The car following me said that most of it came out of the exhaust and the rest was steam coming out of the drivers side air vent thing on the rear panel. At the roadside i checked and found the following:
1. Temp gauge had rocketed up to max setting with red light flashing.
2. Radiator behind front grill freezing cold.
3. Engine red hot (and all the pipes in the engine bay)
4. Water/antifreeze still in the expansion tank (no oil present)
5. Some coolant still in the top up tank.
6. Oil on dip stick is oil with no milkey white stuff.

Question:
1. What's going on?? What was the smoke/seam and how did it get to com out of the exhaust?
2. Could all this be caused by an air lock, i.e air lock in pipework and not getting to radiator to cool the coolant?
3. Could it be themostat not operating correctly?
4. Could it be headgasket?

Prior to this all happening the van had been parked up for a good few months but was fine before.

Thanks in advance.

sounds to me (not the expert ) like your water pump may have fhooked up. Have you had a kind of grinding noise from the engine bay of late?

jed

New water pump last year.... and thermostat for that
What would cause the smoke/steam to come out of the exhaust?

Steam and water vapour out of the exhaust (with engine at normal temp) usually a result of water leaking into the combustion chambers or into the exhaust port. Sounds ominous and you will need to get a professional diagnosis from someone who really knows these engines as they do not use a conventional headgasket and have a complicated cooling system. The exhaust system runs under the engine so bear in mind that water leaking on to it could appear to be from the exhaust outlet and possibly out of the vents too.

Could well be an air lock, or the thermostat or the pump. Worth checking all 3. If oil on dipstick is clear then i wouldn't imagine a head gasket caused it. Sounds like your engine got pretty damn hot so might be worth crossing your fingers.

when engine boils over it blows via the darlek cap into the top up tank which has three small holes in the top to vent when full it blows out of there into engine bay and all over hot exhaust, as system cools the vacuum on the engine side draws coolant from the top up tank, but check level in there it's probably now high.

Thanks all,

AIDEN: thanks for the explanation on the water/steam. What would have caused the engine to boil over? doesn't seem headgaskets are at fault as no oily water in either the water or oil side. As the rad was stone cold should I be looking at thermostat and/or air lock? Had only done about 10 miles and the temp gauge was reading between 1/4 & 1/2 pretty constant. As soon as the smoke/steam I noticed the temp gauge was of the scale and the red warning light on.

Many thanks

Stuck thermostat, boiled out of the cap or split the tank.
cap might be shagged too now

oil in the water is not a issue when the head gaskets go on these anyway, that would be the sealing rings on the barrels mostly.
The head gaskets as such are dry sealing gaskets between the barrel and the head, as the name suggests, no oil ways are through or near them.

what people mostly refer to as head gasket issues are infact the water jacket seals, where the head seals to the main casing and the water jacket.

Its a pressurised system, which normally prevents the coolant boiling off. Its only meant to boil off when overheating leads to overpressure and it vents out of the darlek cap into the overflow tank. If your system doesn't hold pressure then you will lose coolant, either gradually during normal use due to evaporation as it gets warm, or suddenly if it overheats and blows over.

Had a very similar thing happen to me. Hadn't driven it for a while, then got about 5 miles before it overheated without warning (although I wasn't looking at the gauge, so maybe missed the warning!) Surrounded by a huge cloud of steam... Not so much a bus, more like a cumulo nimbus... Pulled over, the coolant level in both the main tank and the overflow tank was really low.

It was only after that, having topped up the coolant and trying to bleed the system that I noticed that my darlek cap didn't seal properly onto the main tank (worn thread on the tank, the cap itself was fine). So it didn't hold much pressure. It was also impossible to bleed the system, cos whenever I squeezed the pipes, air just rushed out around the cap, instead of pushing the coolant around. Replaced the tank, bled the system, now its fine!