Oil Pump - Rotary, excluding BMW «520» from model year 1978 and «520i» since the 1982 model year, in the lubrication system of engines of which a gear-type oil pump is used. The rotary oil pump is driven by a chain from an asterisk mounted on the front end of the crankshaft (from the drive side of the gas distribution mechanism).
An oil filter with a replaceable filter element and a pressure reducing valve is connected in series with the main engine oil line.
Excess pressure in the oil system is relieved by a pressure reducing valve built into the oil pump housing.
On car models «525» And «528i» oil sump - light alloy, finned. On car models «518», «520» And «520i» the oil sump is made of steel sheet.
Rotary oil pump
Oil pump specifications
Pump drive on «518», «520», «520i» carried out by a Simplex roller chain in dimensions 3/8" x 5/32" (the chain can be of two different lengths: normal length - red mark; extended length - green mark); on «525», «528» - single-row roller chain with dimensions 3/8" x 7/32".
Number of chain links: 46.
The chain tension is regulated by the selection of the thickness of the shims installed between the cylinder block and the pump housing.
Since the 1978 model year, some characteristics of the oil filter and pump of BMW engines have been changed «525», «528» And «528i».
Reducing valve opening pressure, kg/cm2: 4.8-5.2.
Clearance between the outer rotor and the pump casing, mm: 0.1+0.05.
Axial clearance of the rotor in the pump housing, mm: 0.035-0.095.
Gap between outer and inner rotors, mm: 0.12-0.20.
Opening pressure of the reducing oil filter, kg/cm2: 2.5±0.2.
Since the 1980 model year, an oil pump with slightly different characteristics has been installed on all models.
Oil pressure at idle, kg / cm2: 0.5-2.0.
Oil pressure at maximum crankshaft speed, kg/cm2: 4-5.
BMW «525», «528i» And «535i»
Gap between the outer rotor and the pump housing, mm: 0.10-0.15.
Lateral clearance between the rotor and the pump housing, mm: 0.04-0.10.
Oil filter reducing valve opening pressure, kg/cm2: 2.5.
Gear oil pump
Oil pressure, kg/cm2:
- at idle: 0.5-1.0;
- at the maximum crankshaft speed: 5.0-6.0.
The length of the pressure reducing valve spring in the free state, mm: 44.
Oil filter
The filter element is changed at every oil change.
Brand:
- «518», «520», «520i»: AC Delco x 18; Fram PH 46; Purflux LS 115;
- «525». «528»: AC Delco AC 72 A; Fram CH 834 PL1; Purflux L178.
Reducing valve opening pressure, kg/cm2: 2.5.
Engine oil
Oil sump capacity, l:
- «518», «520», «520i»: 4,25 (including 0.25 in oil filter);
- «525», «528»: 5,75 (including 0.75 in oil filter);
- «535i»: 6,5 (including cooler) *.
* When changing the oil, the capacity is 5.75 liters, including 0.75 liters in the oil filter.
Used oil: all-weather SAE 20W50.
Oil change interval: every 7500 km or at least twice a year.