what i doubted was the remark in one of your previous posts above that

normally it would be the compression rings,not the oil control rings the compression rings are the two that seal the piston/cylinder so that the combustion gases don't blowby to the crankcase. if your mechanic is saying it is the oil control rings, i'd want to know more.

i would do the compression tests, both dry and wet. this will help isolate the cause of any compression loss to either rings or the valve train. a leak down test will also help in pinpointing the problem. this all assumes you do in fact have a compression loss, as your mechanics believe, and also assumes that it isn't your pcv valve system causing your over-pressure problem.

as others have pointed out, it'll be a lot easier and cheaper to make sure your pcv valve system is working even before doing further tests and diagnosis.

hth

//bc