Oil Pump Inspection

Remove the pump cover.
Check the inner-to-outer rotor radial clearance between the inner rotor (A) and outer rotor (B). If the inner-to-outer rotor radial clearance exceeds the service limit, replace the oil pump.
Inner Rotor-to-Outer Rotor Radial Clearance

Standard (New): 0.02-0.14 mm (0.001-0.006 in.)

Service Limit: 0.20 mm (0.08 in.)

Fig 1: Checking Inner-To-Outer Rotor Radial Clearance Between Inner Rotor And Outer Rotor
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check the housing-to-rotor axial clearance between the rotor (A) and pump housing (B). If the housing-to-rotor axial clearance exceeds the service limit, replace the oil pump.
Housing-to-Rotor Axial Clearance

Standard (New): 0.02-0.06 mm (0.001-0.002 in.)

Service Limit: 0.15 mm (0.006 in.)

Fig 2: Checking Housing-To-Rotor Axial Clearance Between Rotor And Pump Housing
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check the housing-to-outer rotor radial clearance between the outer rotor (A) and pump housing (B). If the housing-to-outer rotor radial clearance exceeds the service limit, replace the oil pump.
Housing-to-Outer Rotor Radial Clearance

Standard (New): 0.10-0.18 mm (0.004-0.007 in.)

Service Limit: 0.20 mm (0.008 in.)

Fig 3: Checking Housing-To-Outer Rotor Radial Clearance Between Outer Rotor And Pump Housing
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Inspect both rotors and the pump housing for scoring or other damage. Replace parts if necessary.
Install the oil pump cover.