Would an S reg Peugeot 406 Coupe 3.0 V6 have a cambelt or chain

it should have a cam belt

GONE ARE THE DAYS OF TIMING CHAINS.

1986 was the last year for a Peugeot chain (205 models xy xw engines). It was TOO strong & lasted forever. Therefore Peugeot could not recommend u change it for 20 quid & labour of 100 quid, every 60,000 miles.
Also, in the days of the timing CHAIN, the water pump was easily accessible on the outside of the engine. You did not have to change it! u could always SEE a problem. Nowadays the water pump is hidden inside, under the timing (cam) belt, & you'd better change it whether it is bad NOW or not.

Timing chains..Rest In Peace.

Who is the timing chain LOVER that gave me a thumbs down? Sorry, buddy, the marketing $$$-world is passing us by.

It is a belt that should be changed about 120,000kms.

The timing belt on the ES9J4 engine what a lovely job to do .
You need to grow an extra hand for this job or just get some extra help .
Its a bit fiddly to do but possible if you know what you are doing .
The tensioning tool you can make out off bolts .
As Trever says (zzzzzz) all ways change the water pump but he is right .
If l remember right as it was 5 years ago when l last did one its 80.000 miles or 8 years which ever comes first.

It has a V6, that is one thing. Well, though, at the wheel, not so sure.

Bisous :)