How old is it? The newer ones were meant to be a lot longer lasting. Mine is an R reg with 108k on it with no rattle at all. The chains/tensioners (i believe VW claimed they were a non serviceable item) can last indefinitely, but can also give way at relatively low milage. Just listen for any nasty rattle sounds around 1000rpm upto 2000rpm. As audi100quattro says, keep your oil clean and change often!
To get the chains done will cast around £600, dependent on whether or not you need a clutch, which if needed is advisable to have done at the same time as the gearbox is out etc.
Another thing to think about is for £1295.00 + Vat you can get a fully recon engine with a warranty (i don't think includes fitting though).
I think I'll save my pennies for the recon engine, should it ever need one!
Hope this helps
