My father in law has a 99 corolla with 120k miles. 3 month, 3,000 miles oil changes since new. Pulled the valve cover, engine is clean. The valve seals are starting to go, a slight puff of blue smoke upon start is visible. What is a good additive for the oil to help the seals? I know there is no miracle fix but its a big job to change the valve seals for this motor and we want to make it last as long as possible.
Last edited: