Oil Pump: Testing and Inspection

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.

DRIVE AND DRIVEN ROTORS






Place the drive and driven rotors into the oil pump body with the mark facing upward.

Inspect Rotor Tip Clearance






Using a feeler gauge, measure the clearance between the drive and driven rotor tips.
Standard tip clearance: 0.110-0.240 mm (0.0043-0.0094 in).
Maximum tip clearance: 0.35 mm (0.0138 in).
If the tip clearance is greater than maximum, replace the rotors as a set.

Inspect Rotor Side Clearance






Using a feeler gauge and precision straight edge, measure the clearance between the rotors and precision straight edge.
Standard body clearance: 0.030-0.090 mm (0.0012-0.0035 in).
Maximum body clearance: 0.15 mm (0.0059 in).
If the side clearance is greater than maximum, replace the rotors as a set. If necessary, replace the oil pump assembly.

Inspect Rotor Body Clearance






Using a feeler gauge, measure the clearance between the driven rotor and body.
Standard body clearance: 0.100-0.175 mm (0.0039-0.0069 in).
Maximum body clearance: 0.30 mm (0.0118 in).
If the body clearance is greater than maximum, replace the rotors as a set. If necessary, replace the oil pump assembly.