I am getting some slight valve ticking - '90 420SEL. There is a tappet that sometimes does not pump up at start up but after a second or so is fine. The noise is not horrible or related to the start up noise. It is on the passenger side of the engine. There appears to be minimum cam wear on the lobes.
My question is what type of oil can I use to minimize the ticking (weight, not brand)? I am currently using Mobil 1 10W-30 (yes, I know it is not MB approved but didn't at the time I changed my oil about 3,000 miles ago). I have 5 qts. of Mobile 1 15W-50 to use with my next oil change.
Should I go ahead and replace the tappets (hydraulic compensators)? I have not been able to determine which one(s) are making the noise.