Help loosing coolant/water

[mills24]

Has anyone had the following problem ...
My car has been loosing coolant about half a expansion tank a week...
I have only seen water leak from the car once when it was on a slope (Left hand-side was lower down than drivers side). was unable to see where it was coming as it was night time, have tried to recreate during day time but nothing comes out (Bo**ocks).. Have checked oil and cannot find any contamination with water.

I think its only loosing water when its being driven and not when its parked ..


Just about to book in with Lotus dealer but thought I would see what you guys think ??

Thanks for your help

Andy

[lotuska]

Most obvious would be the water pump. Only leaks when the car is running.

[M100 TWO]

have a look under tray, behind rubber air dam tray fixed by 4 bolts if the under side is wet have to remove to see, good possibility radiator core leaking where it goes into plastic ends or plug on top of rad under n/s light pod

[Jeffbro]

Dont want to alarm you but a leak in my system, emenating from left hand side of the rad, was the first indication of a head gasket failure. It transpired that combustion gasses were passing from the cylinder into the water jacket and pressurising the system beyond its capacity, forcing coolant out. There were no other apparent signs, oil or water contamination other than the release of pressure when the header tank cap was released. Hope yours is a more straight forward explanation!

[Perth_Elan]

Lets start with what all of us know is the weakness in the cooling system, The Heater valve

This valve is located behind the Cylinder Head on the L/H side, look down past the coolant header tank and you will see it

This valve has a plastic body with a metal housing which rusts away.

I would look at this first, the part has a few cross references including a Volvo part reference!

As for leaking whilst running, not much of a pointer, if it was leaking when not running/cold then that would be a big leak and easy to find. The fact it only looses coolant whilst running/hot/underpressure and only a small amount means it is a very small leak which will get bigger!!!

I would make sure you check coolant everyday until you have found it