Lubrication system characteristics (BMW 3 Series E21)

The engine has a pressure lubrication system. The oil filter is connected in series to the main oil line of the engine immediately after the oil pump.

Oil pump

The Eaton rotary oil pump is driven by a chain from the crankshaft drive toothed pulley mounted on the front end of the crankshaft.

Oil pump characteristics

Rotor outer diameter, mm: 57^-0,025₀.

Inner diameter of the pump body, mm: 57.2^+0,025₀.

Rotor height, mm: 16^-0,015_-0,015.

Pump body depth, mm: 16^+0,050_+0,050.

Radial clearance between the rotor and the pump body, n: 0.10-0.15.

Axial clearance of the rotor in the pump body, mm: 0.035-0.095.

Gap between outer and inner rotors, mm: 0.12-0.20.

Pump cover wear depth, mm: no more than: 0.05.

The distance between the wall of the pump housing and the surface of the drive gear in contact with the hub, mm: 42.7±0.1.

Length of the pressure reducing valve spring in a free state, mm: 68.0.

Pressure reducing valve pressure, kg/cm²: 4.12-4.50.

Oil pressure, kg/cm²:

• at idle: 0.8-1.2;
• at 4000 rpm approx.4.

The low oil pressure indicator lamp lights up when the oil pressure is less than 0.35±0.15 kg/cm².

The dimensions of the 46-link oil pump drive chain are: 3/8" 5/32".

Number of teeth:

• crankshaft pulley: 18;
• oil pump drive gears: 27.

The tension of the oil pump drive chain is adjusted by selecting the thickness of the adjusting gasket installed between the cylinder block and the oil pump housing, which is supplied as spare parts with a thickness of 0.10 and 0.30 mm.

The oil pan is made of stamped steel.

Oil filter

An oil filter with a replaceable filter element and a pressure-reducing valve is connected in series with the main oil line of the engine.



Opening pressure of the pressure reducing valve, kg/cm²: 2.2±0.3. Oil filter brand: "315", "316", "318", "320", "320i": Purolator PC 201; "318i": Purolator PC 253.

Motor oil

Lubrication system capacity, l: 4 (including 0.25 l in the oil filter).

The difference in oil level between the lower and upper marks on the oil dipstick, l: 1.25.

Oil used: HD SAE 10W40.

Replacement frequency: every 7500 km or at least twice a year with replacement of the oil filter.