Function description of crankcase ventilation - RA01001190400X(01-0400)

WARNING: This page does not describe the selected car, but rather 42 other vehicles, including the 1999 Mercedes-Benz S600, 1999 Mercedes-Benz S500, 1999 Mercedes-Benz S420, 1999 Mercedes-Benz S320, and 1999 Mercedes-Benz CL600. However, it is still accessible from the selected car via links, so may be relevant.

Crankcase ventilation at idle speed and midpart load

Fig 1: Function Description Of Crankcase Ventilation At Idle Speed And Midpart Load

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Engine 119.97/98

The blowby gases flow at idle speed and at lower part load out of the front of the crankcase (1) along the left intake duct (3) into the oil separation chamber (11a) in the left cylinder head cover (11).

The blowby gases then flow along the connection line (4) with the 1.5 mm dia. restriction orifice (8) to the combustion chambers.

At the same time, fresh air flows into the crankcase (1) through the vent pipe (5), right cylinder head cover (12), oil separation chamber (12a) and intake shaft (2).

When performing repairs, check the flow through the vent pipes 4 and 5 and also the restrictor trimming (8).

Ventilation at upper part load and full load

Fig 2: Function Description Of Crankcase Ventilation At Upper Part Load And Full Load

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Engine 119.97/98

The blowby gases flow at upper part load and at full load out of the front of the crankcase (1) along the right intake duct (2) into the oil separation chamber (12a) of the right cylinder head cover (12), along the ventilation line (5) into the intake manifold (10) and from there to the combustion chambers.

Entrained engine oil flows through the oil separation chamber (12a) and the downstream syphon (13) into the oil separator (9) in the right cylinder head.

The oil separator (9) with rubber funnel (7) defoams the entrained engine oil.