I was reading the post below and wondered if this applied to a 95 405 TD? I was going to drain and refil the coolant system but this worries me a bit..
"The french in there infinate wisdom built the 405 with dodgy coolant system. There are parts of the coolant system that are higher then the radiator filler hole When you fill your car up you have to make sure you use a header tank and bleed the system carefully. Failure to use a
header tank and bleed properly will lead to air locks and these airlock
can destroy the engine. I am also led to believe they can give symptoms
you describe. Never encounted my them myself but i always use a header to refill. Have a look on
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use it and there is loads of hints/ tips and how to's on bleeding the405 engines plus more.
hth si "
The link no-longer works so I can't see how it's done.
Cheers
Ian