Valve adjustment interval? (1 Viewer)

[Dekeman]

Excellent thread, sorry to raise from the dead, but wondering if I should adjust the valves on my '83. Truck has 84,000 miles, the engine sounds exactly like it should (at least like those referenced as to what a properly adjusted 2F should sound like), compression is 145-150 ish across all six and the cover is not leaking one drop. Truck idles smooth, revs freely, and exhaust doesn't smell rich or lean. I suspect they've never been adjusted in the 40 years since the truck was built. I have a warm garage, a new gasket, and — thanks to everyone here — the knowledge to do it. Have been running Shell Rotella T6 synthetic for last 2 years. Leave well enough alone or be proactive?

 

[OSS]

wondering if I should adjust the valves

I suspect they've never been adjusted in the 40 years since the truck was built.

Hell yes with a capital H.
Toyota recommended adjustment interval is every 24,000 miles.
The valve train wears and typically the valves get tighter with use. When they get too tight, the valve doesn’t seal tight on the seat.
The end game is usually a burnt exhaust valve (or valves) that end up leaking.

 

[Dekeman]

Thank you, sir. How is your polished cover holding up? Thinking of doing the same while I have mine off.

 

[OSS]

Mine was just polished with no coating applied to it afterwards- so raw aluminum eventually oxidizes to dull gray as usual. I knew that but there’s some satisfaction seeing a sparkling valve cover after a head rebuild.