2.5 intercooled turbo engine problems

1992 mitsy pajero swb, engine broke some rockers and got that fixed no problem, a few weeks later it broke the rockers again and cam had 2 be replaced, it went fine for a while and now cam belt keeps coming loose, is there a serious problem here that the machanic can't find?, ive never herd of this b4

is posible that the oil is not comming to the top of the engine ( broken oil pump ) ...... is the head or the cam caps scratched? u change the cam is supose to be smooth , if something is scrantched it stop up the cam ... its happened me with a mitsubishi expo , i had to change the head.

I have a 2500 swb that smashed a rocker and snapped the cam after getting it fixed it has just broken another rocker again (only lasted 5 weeks). Yes there are scratch marks on the cam cover and the pin that holds the cam belt/cog in place had sheered. HELP is it a new head or engine or just a matter of the timing needs to be set up. I am not a machanic but recognised the fault from last time and cant afford to get a machanic in to do the job.