For 1990-2009 cars only
- Clean all parts of sludge, oil, and varnish by soaking in carburetor cleaner or cleaning solvent.
- Inspect for foreign material and determine the source of the foreign material.
- Inspect the oil pump housing and engine front cover for the following conditions:
- Do not attempt to repair the oil pump housing. Replace the oil pump housing if damage is found.
- Inspect the oil pump gears for damage.
- Measure the inner oil pump gear tip clearance in several places.
- Measure the outer oil pump gear tip clearance in several places.
- Measure the oil pump gear side clearance.
- Inspect the pressure regulator valve for the following conditions:
- Inspect the pressure regulator valve spring for loss of tension or bending. Replace the pressure regulator spring if damaged.
- Inspect the oil pump pipe pickup tube and screen assembly for the following conditions:
| • | Cracks or casting imperfections |
| • | Scoring |
| • | Damaged threads |
Important: When deciding oil pump serviceability based on end clearance, consider depth of the wear pattern in the pump cover.
| • | Scoring |
| • | Sticking |
| • | Burrs -- Burrs may be removed using a fine oil stone. |
| • | Looseness -- If the oil pump pipe pickup tube is loose or bent, replace the oil pump pipe pickup tube. |
| • | Broken wire mesh or screen |
| • | Inspect the O-ring seal at the base of the oil pump pickup tube for damage. |
