1.INSPECT OIL PUMP RELIEF VALVE
Coat the oil pump relief valve with engine oil, then check that it falls smoothly into the valve hole by its own weight.
If the oil pump relief valve does not fall smoothly, replace the oil pump assembly.
2.INSPECT OIL PUMP ROTOR
Check the side clearance.
Using a feeler gauge and precision straightedge, measure the clearance between the oil pump drive rotor, oil pump driven rotor and precision straightedge.
0.030 to 0.070 mm (0.00118 to 0.00276 in.)
0.16 mm (0.00630 in.)
If the side clearance is greater than the maximum, replace the oil pump assembly.
Check the tip clearance.
Using a feeler gauge, measure the clearance between the oil pump drive rotor and oil pump driven rotor tips.
0.04 to 0.16 mm (0.00157 to 0.00630 in.)
0.35 mm (0.0138 in.)
If the tip clearance is greater than the maximum, replace the oil pump assembly.
Check the body clearance.
Using a feeler gauge, measure the clearance between the oil pump driven rotor and oil pump body.
0.11 to 0.19 mm (0.00433 to 0.00748 in.)
0.325 mm (0.0128 in.)
If the body clearance is greater than the maximum, replace the oil pump assembly.