Keep the CX or suggestions for alternative?

[cachaciero]

It does have a history of loosing water, not vast quantities, I think most likely due to some hole somewhere expanding when it's hot...

Still pretty certain it's not head gasket, system withstands pressure testing and there is no sign at all of mayo...

A head leak between cylinder and water way will not cause mayo, will result in coolant loss though!

[Stickyfinger]

It can do, due to positive pressure in the coolant system when you turn the car off.

[cachaciero]

It can do, due to positive pressure in the coolant system when you turn the car off.

Well I guess if the water can get past the rings into the sump then yes, just get the feeling that not enough water would enter via this route to produce "mayo" but I could well be wrong. Anyway if there was a water to combustion space leak a "sniffer" should identify it, wouldn't have too much confidence in pressure checking to find a small leak least ways at the pressures normally used.

[oli_25_uk]

Cheers for all this - just about to pick the car up from the garage (after a new fan temperature switch has been installed (along with other things)) - but I'm interested in this suggestion of a 'water to combustion space leak' - What other symptoms would you expect to see going along with such a leak?

OLIx

[cachaciero]

Well there should be combustion products in the coolant and there are sniffing devices which can detect that, believe it's quite a standard piece of kit for many garages. I would look to get a check using such a device if the coolant tests negative for combustion products you could probably forget the gasket. Another thought is that rubber as used in pipes was not of the quality it is today so evaporation through the rubber is a possibility.