TDi water loss

[dazmac]

Hello all,

Having a strange issue with the car losing water.

Temperature remains fine, no problems but after a 50 mile drive and parking up, the water level warning light comes on. (not immediately but upon restarting the car)
No evidence of anything in the water, at tickover it circulates fine. No evidence of water in the oil, or around the oil filler cap (if that is still evident?)
This has all started happening after having the timing belt and thermostat changed about 10000 miles ago, (its happened 3-4 times since this was done)
I had a look around the car today and the only signs of water leaking are from the header tank itself, at the overflow point under the pressure cap.

Any ideas or has anyone experienced the same?

Daz

[the_old_diver]

and the only signs of water leaking are from the header tank itself, at the overflow point under the pressure cap.

It might be worth examining the O-ring in the expansion tank filler cap and the O-ring sealing surface. The cap also contains pressure relief components which might be defective.