Nissan Maxima Service and Repair Manual: Oil pump

Removal and Installation

REMOVAL

1.  Remove the engine from the vehicle. Refer to EM-103, "Removal and Installation".
2.  Remove the upper oil pan. Refer to EM-37, "Removal and Installation (Upper Oil Pan)".
3.  Remove the timing chain. Refer to EM-64, "Removal and Installation".
4.  Remove oil pump assembly.

INSTALLATION

Installation is in the reverse order of removal.

Disassembly and Assembly

1. Oil pump housing
2.  Outer rotor
3.  Inner rotor
4.  Oil pump cover
5.  O-ring
6.  Regulator valve set
7.  Regulator valve
8. Spring
9. Regulator plug
10.  Oil strainer

CAUTION: Before assembly, apply new engine oil to the parts as shown.

DISASSEMBLY

1.  Remove the oil pump cover.
2.  Remove inner rotor and outer rotor from oil pump housing. CAUTION: The outer rotor has directional vanes in relation to the rotation of the oil pump shaft. Note the outer rotor vane direction for assembly.
3.  Remove oil strainer from oil pump housing.
4.  After removing regulator plug, remove spring and regulator valve.

INSPECTION AFTER DISASSEMBLY

Clearance of Oil Pump Parts

• Measure clearance with feeler gauge.
• Clearance between outer rotor and oil pump body (position 1).

• Tip clearance between inner rotor and outer rotor (position 2).

• Measure clearance with feeler gauge and straightedge.
• Side clearance between inner rotor and oil pump body (position 3).
• Side clearance between outer rotor and oil pump body (position 4).
• Calculate the clearance between inner rotor and oil pump body as follows:

1. Measure the outer diameter of protruded portion of inner rotor (position A).
2.  Measure the inner diameter of oil pump body with inside micrometer (position B).

   (clearance 5) = (inner diameter of oil pump body B) - (outer diameter of inner rotor A)

3. If out of specifications, replace oil pump assembly.

Regulator Valve

1.  Visually inspect components for wear and damage.
2.  Check oil pressure regulator valve sliding surface and valve spring.
3.  Coat regulator valve with engine oil. Check that it falls smoothly into the valve hole by its own weight.

   If damaged, replace oil pump assembly.

Regulator Valve Clearance

(Clearance 6) = D (Valve hole diameter) - E (Outer diameter of valve)

If it exceeds the standard, replace the oil pump assembly.

CAUTION:

•  Coat regulator valve with engine oil.
•  Check that it falls smoothly into the valve hole by its own weight.

Assembly

Assembly is in the reverse order of disassembly.

•  Assemble the outer rotor in the correct vane orientation to rotation as noted during disassembly and the inner rotor with the groove on the oil pump cover side.

CAUTION:

•  Do not reuse O-ring.
•  Before assembly apply new engine oil to the parts as specified.