astra clutch question

[markt]

I want to buy a vauxhall astra from a car supermarket, but when the (diesel) engine is on, there is a knocking that can be felt through the clutch when it is depressed. Is this normal for diesels, or should I steer clear? Any other comments from drivers of diesel astras would also be welcome.

[KebabMeister]

It could be something simple like something vibrating against the clutch cable... or it could be something as bad as a clutch release bearing.  If it's the latter then you'd probably have to remove the gearbox to fit a new one (unless it can be access and fitted in situ like normal Vauxhall clutches).