Varnished oil can accumulate on the valve stem near the bottom of the valve guides’ contact. This accumulation of varnish is similar to the happenings…
Tag: Failure
Valves for engines that operate in an overheated system will typically have a narrow band of oil coking near the bottom area of the valve…
Multiple cylinders displayed outlines of the piston crown and the piston crater on the valve heads. This intermittent contact indicated a valve to a piston…
Valves may not display oil degradation, adhesive wear, or fretting if valve lash was too tight. Also if valve lash was too tight valve heads…
Fretting indicates repeated movement in a tight joint. Movement should not occur in the retaining area of the valve. Typically fretting is a result of…