Oil Pump Cleaning and Inspection

WARNING: This page is about a different variant/trim than selected.

Fig 1: Exploded View Of Oil Pump

Courtesy of GENERAL MOTORS CORP.

CAUTION: Refer to Safety Glasses Caution in Cautions and Notices.

Fig 2: Measuring Clearance Between Driven Rotor & Pump Body

Courtesy of GENERAL MOTORS CORP.

Use a feeler gage to measure the clearance between the driven rotor and the pump body. Refer to Engine Mechanical Specifications (LY9) or Engine Mechanical Specifications (LA3) . If clearance is greater than maximum, replace the oil pump.

Fig 3: Measuring Clearance Between Both Rotor Tips

Courtesy of GENERAL MOTORS CORP.

Use a feeler gage to measure the clearance between both rotor tips. Refer to Engine Mechanical Specifications (LY9) or Engine Mechanical Specifications (LA3) . If clearance is greater than maximum, replace the oil pump.

Fig 4: Measuring Oil Pump Inner & Outer Gear-To-Housing Clearance

Courtesy of GENERAL MOTORS CORP.

Use a feeler gage and a straight edge to measure the oil pump inner and outer gear to housing clearance. Refer to Engine Mechanical Specifications (LY9) or Engine Mechanical Specifications (LA3) . If clearance is greater than maximum, replace the oil pump.

Fig 5: Inspecting Oil Pressure Regulating Valve, Oil Pressure Relief Valve & Springs

Courtesy of GENERAL MOTORS CORP.

Inspect the oil pressure regulating valve, oil pressure relief valve and springs for wear or damage.
Inspect oil pump pressure regulating valve and oil pressure relief valve for free movement in their bores.