the only way to really test the ability of your rings is to hook up a boost guage to the crank case of the engine. Run the guage into the car like normal and see what they are doing during true opperation. of coarse this isnt really needed on a stock engine. Do a compression test and a leak down test with the car at operating temperature. On a leak down test anything less that 20 and you are good to go. on a compression test anything within dealer spec or no more than 10% difference and you are good.

the problem with stock engine TC's it the thrust face of the piston ring lands are a very common fail spot. by thrust face i mean 90 degrees from the piston wrist pin. the way that these break may not show up on a typical leack/compression test. i have seen several engines that passed both of these test, but when pulled apart, the piston ring lands were broken. this can cause all kinds of strange harmonics to the piston rings do to the lack of support under typical (dayly driving) or racing/dynoing conditions.

The only engines that i have seen these break on are turbo car. Now add broken ring lands to a turbo car where the cylinder pressures are much great and you have a problem. Not only are you rings not sealing properly while just drinving, but inage how bad they are under boost.

But as some people on here already stated, some pressure coming out of the crankcase is normal. That is why the factory put the PCV system on there. If it wasnt normal you wouldnt need it.