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)
Removing the oil pan (article - Removing the oil pan K4M Nissan Almera)
We unscrew the two bolts of the oil pump
Bolts have different lengths
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.
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
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.
Removing the spring stop
Take out the spring inu
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.
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.
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.
Check the gears for metal chipping, scuffing and tooth wear.
Assemble the pump in reverse order.