Engine Oil Pump - Inspection

INSPECTION





1. Disassemble the oil pump. Engine Oil Pump - Disassembly
2. Clean all oil pump components. Engine Oil Pump - Cleaning
3. Inspect mating surface of the oil pump housing and cover. Replace oil pump if deeply scratched or grooved (minor surface scratches and polishing is normal).
4. Lay a straightedge across the pump cover surface (3). If a 0.025 mm (0.001 in.) feeler gauge can be inserted between cover and straight edge, cover should be replaced.




5. Measure thickness and diameter of outer rotor. If outer rotor thickness measures 9.474 mm (0.373 in.) or less, or if the diameter is 89.174 mm (3.5108 in.) or less, replace outer rotor.




6. If inner rotor measures 9.474 mm (0.373 in.) or less replace inner rotor.




7. Slide outer rotor into body, press to one side with fingers and measure clearance between rotor and body. If measurement is 0.39 mm (0.015 in.) or more, replace body only if outer rotor is in specifications.




8. Install inner rotor into body. If clearance between inner and outer rotors is 0.20 mm (0.008 in.) or more, replace both rotors.




9. Place a straightedge across the face of the body, between bolt holes. If a feeler gauge of 0.077 mm (0.003 in.) or more can be inserted between rotors and the straightedge, replace pump assembly ONLY if rotors are in specification.
10. Inspect oil pressure relief valve plunger for scoring and free operation in its bore. Small marks may be removed with 400-grit wet or dry sandpaper.
11. The relief valve spring has a free length of approximately 49.5 mm (1.95 in.) it should test between 23 - 25 pounds when compressed to 34 mm (1.34 in.). Replace spring that fails to meet specifications.
12. Assemble oil pump.