The reason for the decrease in oil pressure may be a malfunction of the oil pump

The defect can be caused by clogging of the oil receiver screen, a malfunction of the pressure reducing valve, or severe wear of the drive of the pump parts.

The pump is also removed when the chain and sprockets of the pump drive are heavily worn.

When the chain is stretched strongly, a characteristic engine noise appears.

We install the car on a lift or a viewing ditch.

Tools will be required: socket heads for 10, 13, 16, 18, Torx E8, E14, a four-sided wrench, a set of screwdrivers, a retainer for setting the TDC, a camshaft retainer, engine oil, an oil drain container.

Drain the oil from the oil pan (article - Checking and changing the oil in the Nissan Almera engine)

Removal and repair of oil pump K4M Nissan AlmeraRemoval and repair of oil pump K4M Nissan Almera

Removing the oil pan (article - Removing the oil pan K4M Nissan Almera)

We unscrew the two bolts of the oil pump

Removal and repair of oil pump K4M Nissan Almera

Bolts have different lengths

Removal and repair of oil pump K4M Nissan AlmeraRemoval and repair of oil pump K4M Nissan Almera

Lower the pump a little

Remove the chain from the pump sprocket.

Install the parts in reverse order. Tighten the oil pump bolts to 25 Nm.

Inspection and repair of the oil pump

Tools will be required: socket heads 10, 13, Torx E8, square wrench, engine oil, oil drain container, special sealant, wrench 8, pliers, metal ruler, a set of flat feelers.

Removal and repair of oil pump K4M Nissan AlmeraRemoval and repair of oil pump K4M Nissan Almera

Remove the oil pump, as described at the beginning of the article

Drain the oil from the pump

We unscrew the five bolts securing the oil pump cover

Removal and repair of oil pump K4M Nissan AlmeraRemoval and repair of oil pump K4M Nissan Almera

Remove the oil pump cover.

Remove the spring retainer of the pressure reducing valve

Reducing valve spring is preloaded.

Remove the latch carefully, holding the spring stop.

Removal and repair of oil pump K4M Nissan AlmeraRemoval and repair of oil pump K4M Nissan Almera

Removing the spring stop

Remove the spring

Removal and repair of oil pump K4M Nissan AlmeraRemoval and repair of oil pump K4M Nissan Almera

Remove the pressure reducing valve plunger

Measuring the radial clearance between the gears and the pump housing

The gap should be 0.110-0.249 mm.

Removal and repair of oil pump K4M Nissan Almera

We measure the axial clearance of the gears. It should be equal to 0.020-0.086 mm.

If the measured clearances are out of specification, replace the housing or pump assembly.

We wash the pump housing and parts. We remove deposits from the internal cavities of the pump.

Removal and repair of oil pump K4M Nissan Almera

Inspecting the pump housing and cover.

In the presence of cracks, scratches, casting defects, damage to the threaded holes, we replace the housing or the pump assembly.

Check the pressure reducing valve spring for permanent deformation and bending.

We replace the damaged spring.

Removal and repair of oil pump K4M Nissan Almera

Check the gears for metal chipping, scuffing and tooth wear.

Assemble the pump in reverse order.