some other things I noticed, compared to my e320 (inline 6) the 4 cyl inline 4 in my 190e has a lot pressure when I remove the oil fill cap with the engine running (sprays the oil out). I'm thinking this may be the nature of a 4 cyl motor. I have good compression so thinking I'm not having blowby issues. Maybe exhaust valve guides but I would think my exhaust valve seats would be worn such that good compression would not be attainable. I have over 150 psi in each cylinder.