Thanks for the input. I believe that I will go in an check the hydraulic compensators and adjustment with the go-no gauge and also check for bleed down of the unit and the ability to hold pressure. If everything checks out, I am going to go back to the 15w40 dino.

I thought that any oil at a given viscosity rating, like 15W50 should be the same. I am just surprised that the valves are noisier with the synthetic. The inside of my valve covers and head are as clean as the day it was new. The additional valve noise was immediately noticeable on startup after the oil change. It is nosier warm vs. cold. Does the synthetic form a thinner film of oil? One explanation could be that viscosity is a measure of flow and does not have an effect on how thin the film of oil is or the body of the oil. I am guessing.

BD

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87 560 SL
93 300E 2.8
91 300CE-24