If the owner is negligent on on-time oil changes and other maintenance it can definitely be an issue in the reliability of the 1mz. I plan on pulling the valve cover to get a deeper look and see if it would sludge stuff inside or not. Also plan on pulling the oil pan to see if it was actually for sure bearings that made it seized up

@@100mgdYeah, I know what you mean. I do my oil changes every 3k miles. One time I opened up my 1MZ valve covers and there were tubes of oil sludge in some of the narrow passages. No damage to the top end of the motor, no discoloration, good compression, no oil burning, nothing. They really do sludge up easy, it's not just a myth. I fished the sludge out and switched to Full synthetic.