Philippe Oudot wrote: "I got a few weeks ago the same problem
                         than yours and I change the cap, but ...
                         I should ad it's a turbo diesel ...

Philippe,

I believe that my wasserboxer engine and your TD are quite different in 
cooling system design, so I can't comment on what might be the cause of 
your problem.  Actually, I was both pleased and surprised that my fix 
worked, because on my engine there are a lot of cooling trouble spots 
(which I am sure you are aware of from reading this list).  Perhaps someone 
else will read this post and can give you some ideas.

Sorry,
Mike