!!!!! KV6 major water loss and (possibly) no circulation
 

Just got home after a trip on a breakdown truck. Changed the lower engine mount yesterday and the car clearly didn't approve.

Drove a mile and a half, stopped for a couple of mins, set off again and was overheating, temp needle pointing at 12 o'clock and red light on. Parked up where I had just stopped and saw a large puddle!! Car ran for less than 1 min from being stopped.

Breakdown guy cam up about 30-40 mins later, temp needle still at 12 o'clock with red light, he started the engine to try and see what was going wrong (his idea not mine, I was worried about causing hgf). Engine run for about a minute. There water in the expansion tank.

Guy said that water wasn't circulating and that it would be either the water pump or thermostat jammed. I don't think either is likely as the jammed thermostat presumably wouldn't cause the major coolant loss and the water pump was replaced a month ago (although I thought I heard an unusual noise a bit before breaking down?) and I've done just under 100 miles since (been on holiday).

I've looked at the V and no sign of coolant there.

Any ideas anybody? I'm about to have a look underneath. Any help massively appreciated.

Colin.

Hope it turns out to be nothing too serious Colin. What was 'the funny noise' you heard? could it have been the pressure cap releasing due to air lock? hth


Eric

I'd have hoped it it wasn't the water pump but you never know. It was either a genuine or good quality one fitted by Andy at A&L, so it's unlikely but you never know.

The funny noise perhaps sounded a bit like a belt, or a general slight screeching sound. Or I might have imagined it.

I've had a look, found water on the RH inner CV joint, and there appears to be a leak from a coolant hose above that, where it goes into the engine block. The hose has an aluminium corrugated sleeve. Could this have worked loose from the lower engine mount having been shot, causing lots of engine movement e.g. thud when changing in lower gears? To cap it I did the most stupid thing when I stopped before this happened, I somehow managed to put the handbrake on and release the clutch whilst car was still in gear, so it lurched forward (no idea how I managed that, was too busy looking at the queue for the cash point probably). Maybe this was the last straw for the already loose hose and was enough to cause it to leak.

What I really don't get is that the expansion tank is still full but a lot of coolant was lost.

Check the pipe that runs across the front of your subframe - behind the radiator. This pipe - which runs into the oil cooler, can rot and leak in spectacular fashion very abruptly.

Thanks Zeb, the pipe doesn't look bad and I couldn't detect any stray coolant in that area.

Question is, if it is this pipe at the rear bottom driver's side of the engine, wouldn't that cause the expansion tank level to drop?

I'm not sure about the 'water not circulating' diagnosis, the breakdown chap came up with that very quickly but I cannot see how you'd tell so easily.

No point in guessing, start at square one and proceed in an orderly fashion.. :D

If- the tank has water in it, then the water that escaped has been replaced with air. If -- the leak in the pipe only opens under pressure then the tank wont lose water whilst the engine is not running..

I think you need to follow the procedure for refilling your engine with coolant..

Then check for leaks, if the leak is bad enough to make a puddle under the car it should be easy to find.. :}

For the moment, as there if no proof it's correct, ignore the "no circulation" bit untill it can either be verified or disproved.. :)
...

did you check your water before ran the car....because when i done my coolant i did not tighten the cap enough so as soon as i stopped the engine i lost loads out of the expantion tank and thought i had a major problem.....so i filled up again ran the car got rid of the air lock and tightened the cap up tight... no problems since

James - many thanks for the logical advice. I'm 95% certain that the coolant came from the pipe at the back of the engine.

Neal - thanks for the idea, but I've checked all around there and there was no coolant where it shouldn't have been. I last checked the level using the marks on the side (which seem to read a different level to the marker thing inside the tank?).

I've spoken to an ex-Rover technician who thinks that there might be an air lock causing the coolant to stay in the tank.