'88 190e 2.3.

1) recently replaced cylinder head. head completely redone except for cam/rockers. i'm told they were within tolerances. noisy valvetrain on cold start. lasts about 3-4 seconds then begins to quiet. stays slightly noisy until about 40 degrees C. also have slight miss on startup for about 30-60 seconds.

2) oil filters. MANN & MAHLE have a pressure relief valve inside. BOSCH does not. does this matter?

3) 20/50 or 10/40 weight oil in winter? usually use CASTROL GTX.


thanx for any help. rob.