My old Camry with 218,000 miles and original engine (It's a love hate tihing with that car, I love the reliable factor, HATE the stupid car) started smoking on "start up" real bad. At about 200K when the smoke started, I figured it's about time.........
Then one day I noticed the PC valve rubber gasket was all hard and broken. The PC valve couldn't get a good seal in the valve cover. I replaced the gasket and........WHOA,,,,like I over hauled the motor! NO more smoke! I reckon I'm good for another 100K or so.
Ernie