TD5 water loss

[keyboard]

Hi Guys
Got a bit of problem on my 1999 TD5. I thought I was a water leak by now I am not too sure. Fisrt of all I noticed that the bottle was empty one day last week. This in itself was unusual as the water bottle never goes down. On that particular day I topped up the bottle and kept an eye on it. Then I noticed that if you drived the car. and let it coll down for 24/48 hours and then went to open the water bottle, you would hear the pressure relase and the water bottle would fill up with water. Is this normal (My mechanic says they all do this, but I never noticed it before). I also notice a water mark on the small pipe on the top RHS of the rad and also on the bottom LHS on the pipe that goes into a big platic Y peice.

Has anyone come across anything similar.

Am i looking at
1) a water leak
2) A pressure problem
3) Amore sinister problem


Any help or ideas would be appericated

[Dozey]

I had a similar problem which was poor starting coupled with water loss. The pressure released when I topped up the bottle was far more than usual. It turned out to be a head gasket leak and the poor starting was water sitting on the piston. I was lucky, the head was ok. Now it's fixed the pressure release when I loosen the cap is just a gentle hiss.