Oil Pump: Testing and Inspection

1. Inspect body clearance.
Using a thickness gauge, measure the clearance between the driven rotor and pump body.
Standard clearance: 0.10 - 0.18 mm (0.0039 - 0.0069 inch)
Maximum clearance: 0.30 mm (0.0118 inch)
If the clearance is greater than maximum, replace the oil pump rotor set and/or pump body.





2. Inspect tip clearance.
Using a thickness gauge, measure the clearance between the drive and driven rotor tips.
Standard clearance: 0.11 - 0.24 mm (0.0043 - 0.0094 inch)
Maximum clearance: 0.35 mm (0.0138 inch)
If the clearance is greater than maximum, replace the oil pump rotor set.





3. Inspect side clearance.
Using a thickness gauge and precision straight edge, measure the side clearance, as shown.
Standard clearance: 0.03 - 0.09 mm (0.0012 - 0.0035 inch)
Maximum clearance: 0.15 mm (0.0059 inch)
If the clearance is greater than maximum, replace the oil pump rotor set and/or pump body.





4. Inspect relief valve.
Coat the relief valve with engine oil and check that it falls smoothly into the valve hole by its own weight.
If the valve does not fall smoothly, replace the valve and/or oil pump assembly.