hello and welcome Craig
theres not really that much on the engine that goes wrong
there are some few things that pop up the egr valve can go faulty and the chains and the throttle body needs cleaning from time to time
as IDI amin said only real way to check the chains is to take the rocker cover off look for slack in the chain between the sprockets then with a torch look down the front of the chain and make sure the black front guide rail is intact
then at the rear of the engine look at the shape of the tensioner screwed in to the block the nut will be one of 3 types with the car being a 2002 you should see a tensioner that has a flat top with nicks on the corners(one with the green o-ring in the pic) if you have a tensioner that has a tit on the back then it has the latest style tensioner hers a picture of the tensioner nut you can see the nicks and the nipple the circled one is the current revision
and for the record ""oh how wrong your dad was all this time 🙂"" had mine 10 years never had an issue when the oil is changed at 3-5000 mile intervals
only when its left to the vauxhall 20k miles services intervals or people just not changing the oil often enough the engines had problems 🙂 the oil got to dirty and blocked the oil jet causing the chain to run dry