Oil Pump: Service and Repair

REMOVAL
1. Remove the timing chain cover.





2. Remove the relief valve plug, gasket, spring and valve (Fig. 59). Discard the gasket.





3. Remove mounting screws and oil pump cover (Fig. 60).
4. Remove oil pump inner and outer rotors (Fig. 60).
5. Inspect oil pump for wear.

CLEANING
Wash all parts in a suitable solvent and inspect carefully for damage or wear.

INSPECTION
Mating surface of the oil pump cover should be smooth. Replace pump cover if scratched or grooved.





Lay a straightedge across the pump cover surface (Fig. 61) . If a 0.076 mm (0.003 inch) feeler gauge can be inserted between cover and straightedge, cover should be replaced.





Figure 62





Figure 63

Measure thickness (Fig. 62) (Fig. 63) and diameter of rotors. If either rotor thickness measures 14.956 mm (0.5876 inch) or less, or if the diameter is 82.45 mm (3.246 inches) or less, replace rotor set.





Slide outer rotor into timing chain cover pump body Press rotor to the side with your fingers and measure clearance between rotor and pump body (Fig. 64). If clearance is 0.19 mm (0.007 inch) or more, and outer rotor is within specifications, replace timing chain cover.





Install inner rotor into timing chain cover pump body (Fig. 65) . Inner rotor should be positioned with chamfer up or toward engine when cover is installed. This allows easy installation over crankshaft. If clearance between inner and outer rotors is 0.150 mm (0.006 inch) or more, replace both rotors.





Place a straightedge across the face of the timing chain cover pump body, between bolt holes (Fig. 66) . If a feeler gauge of 0.077 mm (0.003 inch) or more can be inserted between rotors and the straightedge, and the rotors are within specifications, replace timing chain cover.
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.
The relief valve spring has a free length of approximately 49.5 mm (1.95 inches). The spring should test between 100 and 109 N (22.5 and 24.5 pounds) when compressed to 34 mm (1-11/32 inches). Replace spring that fails to meet these specifications.
If oil pressure was low and pump is within specifications, inspect for worn engine bearings or other reasons for oil pressure loss.

INSTALLATION





1. Lubricate both oil pump rotors using petroleum jelly or lubriplate and install in the timing chain cover. Use new parts as required (Fig. 67).
2. Position the oil pump cover onto the timing chain cover. Tighten cover screws to 14 Nm (125 inch lbs.) torque.
3. Make sure that inner ring moves freely after cover is installed.
4. Install the timing chain cover.
5. Squirt oil into relief valve hole until oil runs out.
6. Install the relief valve and spring.
7. Using a new pressure relief valve gasket, install the relief valve plug. Tighten the plug to 20 Nm (15 ft. lbs.) torque.
8. Install oil filter that has been filled with oil.