My B6 140 Passat sport has a weird problem. It uses water very slowly with an occasional quicker loss of say 150ml. Just done 2500 miles in France with lots of motorway but only used 200Ml.
I have had it pressure tested and had replaced (not in this order) Radiator, header tank and cap, cross pipe below rad, a couple of hoses, most of the hose clips and had system ceramic coated so porous head problem should be negated, my garage are renowned VW specialists and still head scratching.
Don't know if it is significant but engine stays pressurised for at least a couple of days, enough to hold water at the minimum mark then return to above maximum mark when header tank cap is removed. Can hear pipes creak as pressure released too.
Garage is of opinion that its not head gasket and don't feel cost of checking that is justified - they are very honest reliable folk!
Any suggestions or similar experiences???
Mystery water loss
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