unexplained loss of water Audi A6 Pd 1.9 TDI

[Mike G]

I'm having big probs with loss of water with no obvious leaks. Changed water pump and radiator but I am still loosing a header tank, about 3 pints on runs of about 50 miles. It seems to lose more water when doing 2500 rpm and above..I'm not covinced it is the head gasket as no contamination in oil or water. I have put some concentrated uv liquid in the header tank and will check with a uv light in a few days. Also changed the header tank cap...any other suggestions would be most helpful.

[hitachi]

I'm having big probs with loss of water with no obvious leaks. Changed water pump and radiator but I am still loosing a header tank, about 3 pints on runs of about 50 miles. It seems to lose more water when doing 2500 rpm and above..I'm not covinced it is the head gasket as no contamination in oil or water. I have put some concentrated uv liquid in the header tank and will check with a uv light in a few days. Also changed the header tank cap...any other suggestions would be most helpful.

I have same problem try pressure test on car by driving not just ticking over. thats how i found mine had too much pressure. I had changed rad cap & exp bottle & radiator before we found pressure problem. best of luck.

[Lex Luthor]

I'm having big probs with loss of water with no obvious leaks. Changed water pump and radiator but I am still loosing a header tank, about 3 pints on runs of about 50 miles. It seems to lose more water when doing 2500 rpm and above..I'm not covinced it is the head gasket as no contamination in oil or water. I have put some concentrated uv liquid in the header tank and will check with a uv light in a few days. Also changed the header tank cap...any other suggestions would be most helpful.

Is it an auto box ?

[mr m]

I'm having big probs with loss of water with no obvious leaks. Changed water pump and radiator but I am still loosing a header tank, about 3 pints on runs of about 50 miles. It seems to lose more water when doing 2500 rpm and above..I'm not covinced it is the head gasket as no contamination in oil or water. I have put some concentrated uv liquid in the header tank and will check with a uv light in a few days. Also changed the header tank cap...any other suggestions would be most helpful.

I have same problem on my A6,did you found out what was wrong,could please let me know?