doing a diy cambelt change how do i check if the dephaser needs replaced?

[delcbr]

my car does sound a bit like a diesel which i thought was odd but since iam doing a cambelt change soon iam thinking i should replace this pulley.
being a mechanical engineer can someone tell me aprt from the diesel noise what should i be looking for to determine if its worn or in good condition?

 

[delcbr]

anyone?
what makes them noisy then?

 

[sophiesdad]

they can wear inside , its an oil filled unit , you can check it by grabbing it, and trying to turn in either direction , you should only get very minor movement ,
they normally rattle , (like a diesel most would say ) when running . if in doubt i would replace it while the belts are off. aprrox £120ish though.

 

[delcbr]

thanks Andy at last someone replys lol!!!!!!!!!!
is that £120 from renault?