Hi Dan,
Well I do always replace every 10.000KM the oil with 5W40 and filter, it always have used this oil in it’s life time. The timing belt have been replaced but it did it before to. New CV joints. New upper engine thermostat it also did it before and after this. New filters. And some stuff around the car like wheels and headlights but that shouldn’t cause the problem.
It got 197.000KM in the clock or 122,410 miles. It’s a 6 speed manual. The camshaft have been checked and it was stated “okay” but I will maybe replace it when the timing belt needs to be done again.
-Max