as said mileage aint really a good indicator on 16v's, some have had easy lives, others have been ragged constant since day 1
wet n dry compression test will give you an idea of how worn the rings are
also, look for the usual, blue smoke @ high rpms = engine breathing heavy/worn rings, blue smoke on idle = worn valve guides
not hard or expensive to rebuild a head. and you can change bearings and piston rings without having to remove the engine. u just need the sump & head off
