I need help please. I have a 1985 500SEC (Euro), with 200K miles. Car has run flawlessly, but has developed an increasingly loud ticking noise from the passenger side (right) engine compartment. Visible thru the oil-fill hole on the valve cover, are grooves (not very deep) on the camshaft lobe. Local dealer said (from listening only) that it could be a rocker or lifter, but I'm wondering if I only replace rockers and lifters, without replacing the camshaft, is this a wise thing to do...or should I replace the camshaft also? Another mechanic said that the lines on the camshaft lobes are normal, but I would like to hear what the experts on this forum can offer. I plan to remove the valve covers and inspect the entire cam for wear, but by visual inspection, how do you tell if the the cam lobes are too worn? (forgot to mention that the oil tubes appear to be flowing well, so that concern is ruled out). Also the service foreman at the dealer mentioned that it only appears to be on the right side, but I will be pulling the valve covers on each side to inspect both cams, but the loud ticking sound is coming from the right side. PLEASE...WHAT SHOULD I DO?? (BTW, I will be replacing the timing-chain, top rails, tensioner and sprocket, during the repair.)