Citroen xsara picasso 2.0 hdi coolant loss

[nomis1981]

Hi I have 53 plate citroen xsara picasso 2.0 hdi and have had problems with the coolant since I bought it in September I noticed the bleedscrew cap on thermostat cover was worn away by the engine cover so I replaced it and trimmed up the cover so it won't do it again and refilled the expansion tank with antifreeze since then I've been losing coolant through the expansion tank cap so bought another cap and I'm still losing it I've had a smell of the expansion tank with the cap off and can't smell any fumes can someone please help

[RichardW]

Engine cold, take the cap off - does it hiss? Refit cap start engine, run for a minute or two, stop engine, cap off does it hiss? With cap off and engine running look in header tank, do you see bubbles rising? Answer yes to any of these, and likely the head gasket is away....

[nomis1981]

Thank for your reply but Could it be by any chance that the cooling system ain't bled properly and if it is head gasket how easy are they to do?