W204 C63 relationship between camshaft、lifter wear and oil viscosity guess
I browsed through the original factory maintenance manual and discovered an interesting thing that is rarely mentioned: oil pressure. And tests were conducted on five m156 units, and the results were astonishing. The original factory maintenance manual requires that the oil pressure should reach above 4.4bar at 3000RPM. However, on the five m156 units using 0w40, the oil pressure would never exceed 4.0bar, which is far below expectations!
And I used a micrometer to measure the bearing bush clearance, which was between 0.009mm and 0.01mm! The clearance of the bearing bush is extremely large,This is a pure racing car design, so if the engine oil is thin, the oil pressure will disappear at the crankshaft bearing. This is also why the m156 will wear out the camshaft and the hydraulic top barrel, and even destroy the bearing bush.
So I think m156 should use engine oil with a higher viscosity. Of course, all of this is just my guess. I hope it can draw attention and have some capable people participate in the discussion.
Last edited by vasilyang; Dec 9, 2025 at 11:49 AM.
-0w- oil was a break through for cleaner running and better miles per gallon. Why do you think they are now running 0W-10 and 0w-20 oil's ? That stuff is like water and has very little drag to it especially in the oil pump and actually frees up horsepower.
-0w- oil was a break through for cleaner running and better miles per gallon. Why do you think they are now running 0W-10 and 0w-20 oil's ? That stuff is like water and has very little drag to it especially in the oil pump and actually frees up horsepower.







