Design and specification of engine lubrication system (Mercedes-Benz E-Class W123)

The pressure lubrication system, created by an internal gear pump with an eccentric rotor, provides lubrication to the crankshaft, connecting rod upper ends and camshaft bearings. Since the 1985 model year, oil from the lubrication system is supplied under pressure to hydraulic tappets, which provide automatic compensation of gaps in the valve timing mechanism.

Oil pump

The oil pump drive gear is mounted on two flats on the front end of the crankshaft (between the crankshaft sprocket and the accessory drive belt pulley). The pump body is made directly in the camshaft drive cover and is closed on the engine side by a cover.

Characteristic	Meaning
Oil pressure on a warm engine, kg/cm²
at idle, not less than	0,3
at a crankshaft speed of 3000 rpm, not less than	3,0
Valve opening pressure on a warm engine, kg/cm²
pressure reducing valve	4,5 ⁺⁰ _–0,8
bypass valve	3,5

Oil filter

Oil filter of reserve design, with replaceable filter element.

Characteristic	Meaning
Brand and type of filter	Knecht AW168 or Mann H 614N
Brand and type of replacement element	Mann W 719/3
Brand and type of replacement element Bosch
M 102	1.457.42.9605 and 1.457.42.9606
M 115	1.457.42.9113
M 123	1.457.42.9113 and 1.457.42.3105
M 110	1.457.42.9610

Motor oil

Characteristic	Meaning
Lubrication system capacity, l
at first filling	5,0
when changing oil	4,5 (including filter)
Difference between "mini" and "maxi" marks on the oil dipstick, l	1,5
Oil used	SAE 10W40 or 10W50 (CCMC classification: 04; according to API classification: AO)
Replacement frequency	every 10 thousand km or at least twice a year