Discoloration on Cam Lobes

[edgemar]

Was doing the valve gasket and noticed some discoloration on the rear lobes of the cam. Everything is smooth no real scoring, but there some rust colored spots on them. Could it be a lack of lubrication or am i just being an alarmist. 135k miles on the engine. Let me know your thoughts! Thx!

[wdfifteen]

Lack of lube would result in rough, burned (blue) looking streaks on the contact (bump) side of the lobe. I think what you are looking at is oil residue built up on the heal side of the lobe due to a lack of contact. Perfectly normal.

[Bob Kontak]

Originally Posted by wdfifteen

I think what you are looking at is oil residue built up on the heal side of the lobe due to a lack of contact. Perfectly normal.

+1. Rocker arm should not touch there or you would have other issues given zero or negative valve lash.

Hit it with some scotch-brite to see if it scrubs off for peace of mind.

[edgemar]

thanks for the input! I won't worry about it.