Toyota, okay, but Camry's valve stem replacement every 90,000 mile possible. Because it's blue smoke from exhaust pipe. That I always pulled off the engine head many times by myself to replace valve stems and clean off a mess the oil mud yuck (harder oil buildup all over valve and spring with twin cam).... Two times, I replace 16 valve stem. And replace whole engine kits to stop oil leak seal, looks bad .... It's like seal turns harden and crack, worn out. I tell you all people, that Toyota same problem, just like America car style. It same thing. Both same and nothing better. Thank you.