Nissan Xterra. Manual - part 493

OIL PUMP

LU-15

< REMOVAL AND INSTALLATION >

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• Bleed air from passages in lines and hoses, such as in cooling system.

• After cooling down engine, again check oil/fluid levels including engine oil and engine coolant. Refill to spec-

ified level, if necessary.

• Summary of the inspection items:

*Power steering fluid, brake fluid, etc.

Item

Before starting engine

Engine running

After engine stopped

Engine coolant

Level

Leakage

Level

Engine oil

Level

Leakage

Level

Transmission/
transaxle fluid 

A/T and CVT Models

Leakage

Level/Leakage

Leakage

M/T Models

Level/Leakage

Leakage

Level/Leakage

Other oils and fluids*

Level

Leakage

Level

Fuel

Leakage

Leakage

Leakage

Exhaust gas

—

Leakage

—

LU-16

< UNIT DISASSEMBLY AND ASSEMBLY >

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OIL PUMP

UNIT DISASSEMBLY AND ASSEMBLY

OIL PUMP

Disassembly and Assembly

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DISASSEMBLY

1. Remove oil pump cover.
2. Remove inner rotor and outer rotor from oil pump body.
3. Remove the regulator valve plug, regulator valve spring and regulator valve.

INSPECTION AFTER DISASSEMBLY 

Clearance of Oil Pump Parts

• Measure radial clearance using a suitable tool.

1.

Oil pump body

2.

Oil pump outer rotor

3.

Oil pump inner rotor

4.

Oil pump cover

5.

Regulator valve plug

6.

Regulator valve spring

7.

Regulator valve spring

8.

Regulator valve

PBIC2826E

Body to outer rotor (position 1)
Refer to 

LU-18, "Standard and Limit"

.

Inner rotor to outer rotor tip (position 2)
Refer to 

LU-18, "Standard and Limit"

.

PBIC2827E

OIL PUMP

LU-17

< UNIT DISASSEMBLY AND ASSEMBLY >

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• Measure side clearance using suitable tools.

• Calculate the clearance between inner rotor and oil pump body as

follows.

1. Measure the inner diameter of oil pump body to brazed portion

(position 5) using suitable tool.

2. Measure the outer diameter of protruded portion of inner rotor

(position 6) using suitable tool.

3. Calculate the clearance using the following formula.

• (Clearance) = (Inner diameter of oil pump body) - (Outer diameter of inner rotor)

Regulator Valve Clearance

Check regulator valve to oil pump cover clearance using the following formula.

• (Clearance) = D

1

 (Valve hole diameter) - D

2

 (Outer Diameter of

valve)

CAUTION:

• Coat regulator valve with engine oil.

• Check that it falls smoothly into the regulator valve hole by its

own weight.

ASSEMBLY

Installation is in the reverse order of removal.

NOTE:

• Install oil pump inner rotor with the groove facing the oil pump

cover side.

• Install the oil pump outer rotor with the punch mark facing the oil

pump cover side.

Body to inner rotor (position 3)
Refer to 

LU-18, "Standard and Limit"

.

Body to outer rotor (position 4)
Refer to 

LU-18, "Standard and Limit"

.

PBIC2828E

PBIC0821E

Inner rotor to brazed portion of housing 
clearance
Refer to 

LU-18, "Standard and Limit"

.

Regulator valve to oil pump cover
Refer to 

LU-18, "Standard and Limit"

.

PBIC2829E

PBIC2830E

LU-18

< SERVICE DATA AND SPECIFICATIONS (SDS) 

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SERVICE DATA AND SPECIFICATIONS (SDS)

SERVICE DATA AND SPECIFICATIONS (SDS)

SERVICE DATA AND SPECIFICATIONS (SDS)

Standard and Limit

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OIL PRESSURE

Unit: kPa (kg/cm

2, psi)

*: Engine oil temperature at 80

°C (176°F) 

OIL PUMP

Unit: mm (in)

REGULATOR VALVE

Unit: mm (in)

ENGINE OIL CAPACITY (APPROXIMATE)

Unit:   (US qt, Imp qt)

Engine speed

Approximate discharge oil pressure*

Idle speed

More than 98 (1.0, 14)

2,000 rpm

More than 294 (3.0, 43) 

6,000 rpm

More than 392 (4.0, 56.8) 

Body to outer rotor (Position 1)

0.120 - 0.195 (0.0047 - 0.0077)

Inner rotor to outer rotor tip (Position 2)

0.060 - 0.160 (0.0024 - 0.0063)

Body to inner rotor (Position 3)

0.030 - 0.070 (0.0012 - 0.0028)

Body to outer rotor (Position 4)

0.050 - 0.090 (0.0020 - 0.0035)

Inner rotor to brazed portion of housing 

0.045 - 0.091 (0.0018 - 0.0036)

Regulator valve to oil pump cover

0.025 - 0.070 (0.0010 - 0.0028)

Drain and refill

With oil filter change

5.1 (5-3/8, 4-1/2)

Without oil filter change

4.8 (5-1/8, 4-1/4)

Dry engine (Overhaul)

6.3 (6-5/8, 5-1/2)