Disassembly and assembly of the oil pump (BMW 3 Series E21)

Removing and installing the oil pump is quite simple (see "Removal and installation the oil pump").

Disassembling the oil pump

Remove plug 1, spring 2 and plunger 3 of the pressure reducing valve.

Remove cover 4 of the oil pump.

Wash and blow out the oil pump parts with compressed air.

Checking the technical condition of oil pump parts

Measure the free length of the pressure reducing valve spring, which should be 68 mm.

Check the clearances between the outer rotor and the oil pump housing and between the inner and outer rotors, as well as the recession of the outer rotor relative to the end of the oil pump housing.

If the clearance between the outer rotor and the oil pump housing is greater than the norm, replace the pump housing. If the clearance between the inner and outer rotors exceeds the limit, replace the rotors. If the sinking of the outer rotor exceeds the limit, replace the oil pump housing.

To remove the inner rotor, press off the oil pump drive flange using a universal two-lever puller. Do not press off the flange using a lever.

When pressing the oil pump drive flange, it is necessary to maintain dimension "A", equal to 42.7+0.1 mm.





The full-flow oil filter with a replaceable filter element is connected in series to the main oil line.

Assembly and installation of the oil pump

The oil pump assembly is performed in the reverse order of removal. In this case, it is necessary to check the clearances between the outer rotor and the oil pump housing and between the inner and outer rotors, as well as the recession of the outer rotor relative to the end of the oil pump housing.

Install the oil pump on the cylinder block. Install the toothed pulley of the oil pump drive and tighten the bolts of the pump mounting bracket so that the pump body is not subjected to loads.

Install the oil pan, applying Atmosit type sealant to the front and rear of the gasket.