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 does not, replace the relief valve. If necessary, replace the oil pump assembly.

2. Place drive and driven rotors into oil pump body.



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

3. Inspect rotor side clearance.



- Using a feeler gauge and precision straight edge, measure the clearance between the rotors and precision straight edge.

Standard side clearance: 0.030 - 0.090 mm (0.0012 - 0.0035 inch)
Maximum side clearance: 0.15 mm (0.0059 inch)

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

4. 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 inch)
Maximum tip clearance: 0.35 mm (0.0138 inch)

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

5. 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 inch)
Maximum body clearance: 0.30 mm (0.0118 inch)

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