Oil Pump: Testing and Inspection

1. Inspect relief valve. Coat the valve with engine oil and check that it falls smoothly into the valve hole by its own weight. If it doesn't, replace the relief valve. If necessary, replace the oil pump assembly.





2. Inspect drive and driven rotors.
a. Inspect rotor body clearance. Using a thickness gauge, measure the clearance between the driven rotor and body.
Standard body clearance:
0.10-0.16 mm (0.0039-0.0063 in.)
Maximum body clearance:
0.20 mm (0.0079 in.)

If the body clearance is greater than maximum, replace the rotors as a set. If necessary, replace the oil pump assembly.





b. Inspect rotor tip clearance. Using a thickness gauge, measure the clearance between the drive and driven rotor tips.
Standard tip clearance:
0.04-0.16 mm (0.0016-0.0063 in.)
Maximum tip clearance:
0.20 mm (0.0079 in.)

If the tip clearance is greater than maximum, replace the rotors as a set.