Oil Pump

This procedure covers removal and replacement of the oil pump on a 2014-2018 Chevrolet Silverado 1500 with the 5.3L L83 V8 engine, requiring removal of the oil pan and timing cover.

Warnings

Tools required

Parts

• Oil pump assembly × 1 — ACDelco 12677836 or equivalent
• Oil pump pickup tube O-ring × 1 — Use OEM specification
• Timing cover gasket × 1 — Use OEM specification
• Oil pan gasket × 1 — Use OEM specification
• Oil filter × 1 — ACDelco PF63E or equivalent
• Oil drain plug crush washer × 1 — Use OEM specification
• RTV silicone sealant × 1 — ACDelco 88901148 or equivalent

Fluids

• ACDelco dexos1 0W-20 — 8.5 qt
• ACDelco DEX-COOL (Orange) — 2 qt

Preparation

1. Position vehicle on level surface and engage parking brake
2. Disconnect negative battery cable
3. Raise and securely support vehicle on jack stands at manufacturer-specified lift points
4. Remove engine cover (plastic cover over engine)
5. Remove front skid plate if equipped
6. Place drain pan under engine oil drain plug

Procedure

1. 1

   Drain engine oil and coolant
   Remove oil drain plug and drain engine oil completely into drain pan. Replace drain plug with new crush washer. Drain coolant from radiator petcock and lower radiator hose into separate container for reuse if clean. Remove oil filter.
   Torque spec

   Oil Drain Plug35 Nm (26 lb-ft)
2. 2

   Remove accessory drive components
   Remove serpentine belt by rotating tensioner clockwise. Remove air intake duct and air filter housing. Disconnect electrical connectors from alternator and A/C compressor. Remove alternator mounting bolts and set alternator aside. Remove power steering pump mounting bolts and secure pump aside without disconnecting hoses.
   Torque spec

   Mounting Bolts60 Nm (44 lb-ft)

   Electrical Connector Bolts8 Nm (6 lb-ft)
3. 3

   Remove harmonic balancer
   Remove the fan shroud bolts and radiator support to access crankshaft balancer. Remove crankshaft balancer bolt (typically 37mm socket required, rotate counterclockwise). Use harmonic balancer puller to remove balancer from crankshaft. Do not hammer or pry on balancer.
   ⚠The balancer bolt is extremely tight. Use a breaker bar and secure the crankshaft from rotating by placing transmission in Park.
4. 4

   Support engine and remove motor mount
   Install engine support fixture or use engine hoist to support engine weight. Remove right-side engine mount bolts. Raise engine slightly (approximately 1-2 inches) to provide clearance for timing cover removal. Ensure all hoses and wiring have adequate slack.
   Torque spec

   Mounting Bolts60 Nm (44 lb-ft)
5. 5

   Remove oil pan
   Remove all oil pan bolts in a crisscross pattern starting from the outer edges. Carefully separate oil pan from engine block using a plastic gasket scraper if needed. Clean all old gasket material and RTV from both oil pan and engine block mating surfaces thoroughly. Inspect oil pan for damage or warping.
   ℹ️Some oil pan bolts may be different lengths. Note their positions during removal for correct reassembly.
   Torque spec

   Oil Pan Bolts12 Nm (9 lb-ft)
6. 6

   Remove timing cover
   Disconnect crankshaft position sensor electrical connector. Remove all timing cover bolts, noting that 8mm bolts require specific torque. Carefully pry timing cover away from engine block using pry points if provided. Remove timing cover gasket and clean all mating surfaces on both block and cover.
   ℹ️Timing cover bolts are various lengths. Organize them by position to ensure correct reinstallation.
   Torque spec

   Cover Bolts20 Nm (15 lb-ft)

   Sensor Bolts14 Nm (10 lb-ft)
7. 7

   Remove oil pump pickup tube
   From inside the oil pan area, remove the oil pump pickup tube mounting bolt. Carefully pull pickup tube from oil pump housing. Inspect pickup tube screen for debris or damage. Replace O-ring on pickup tube.
   Torque spec

   Oil Pump Pickup Tube12 Nm (9 lb-ft)
8. 8

   Remove oil pump
   Remove oil pump mounting bolts securing pump to engine block. Carefully slide oil pump assembly off the crankshaft. Note the position and orientation of oil pump drive components. Inspect crankshaft oil pump drive surface for wear or damage.
   ℹ️The oil pump slides onto the crankshaft snout. Do not force or pry excessively to avoid damaging alignment.
   Torque spec

   Oil Pump Bolts12 Nm (9 lb-ft)
9. 9

   Install new oil pump
   Apply light coat of clean engine oil to crankshaft snout and oil pump gears. Align new oil pump onto crankshaft, ensuring proper engagement with drive mechanism. Install oil pump mounting bolts and torque to specification in a crisscross pattern.
   ⚠Verify oil pump rotates freely by hand before final installation. Binding indicates misalignment.
   Torque spec

   Oil Pump Bolts12 Nm (9 lb-ft)
10. 10

    Install oil pump pickup tube
    Install new O-ring on oil pump pickup tube, lubricating with clean engine oil. Insert pickup tube firmly into oil pump housing until fully seated. Install and torque pickup tube mounting bolt to specification.
    Torque spec

    Oil Pump Pickup Tube12 Nm (9 lb-ft)
11. 11

    Install timing cover
    Install new timing cover gasket, ensuring proper alignment with dowel pins. Apply small bead of RTV sealant at engine block-to-oil pan junction points. Position timing cover onto engine block, aligning with crankshaft and dowel pins. Install all timing cover bolts finger-tight, then torque 8mm bolts to specification in proper sequence (center outward). Reconnect crankshaft position sensor.
    Torque spec

    Cover Bolts20 Nm (15 lb-ft)

    Sensor Bolts14 Nm (10 lb-ft)

    Gasket Surface Bolts26 Nm (19 lb-ft)
12. 12

    Install oil pan
    Install new oil pan gasket onto engine block. Apply small beads of RTV sealant at front and rear cover-to-block junctions. Position oil pan and install all bolts finger-tight. Torque oil pan bolts to specification in a crisscross pattern from center outward.
    ℹ️Allow RTV sealant to cure for at least 2 hours before filling with oil per manufacturer recommendations.
    Torque spec

    Oil Pan Bolts12 Nm (9 lb-ft)
13. 13

    Reinstall harmonic balancer and accessories
    Clean crankshaft snout and harmonic balancer bore. Install harmonic balancer onto crankshaft, aligning keyway. Install and torque crankshaft balancer bolt to manufacturer specification (typically 240 Nm plus 150 degree turn). Reinstall power steering pump, alternator, and all electrical connectors. Lower engine onto motor mount and install mount bolts. Remove engine support fixture.
    Torque spec

    Mounting Bolts60 Nm (44 lb-ft)

    Electrical Connector Bolts8 Nm (6 lb-ft)
14. 14

    Final assembly and fluid fill
    Reinstall all remaining components in reverse order of removal: serpentine belt, air intake, radiator support, fan shroud, skid plate. Install new oil filter. Fill engine with 8.5 quarts of ACDelco dexos1 0W-20 oil. Refill coolant system with ACDelco DEX-COOL to proper level. Reinstall engine cover. Reconnect negative battery cable.

Reassembly

1. Ensure all electrical connectors are fully seated and secured
2. Verify serpentine belt is properly routed on all pulleys
3. Double-check that all drain plugs and bolts are installed and torqued
4. Confirm no tools or rags are left in engine compartment

Verification

• Start engine and verify oil pressure gauge shows normal pressure within 5 seconds
• Inspect for oil leaks around oil pan, timing cover, and oil filter while engine idles
• Check for coolant leaks around timing cover area
• Allow engine to reach operating temperature and verify no leaks develop
• Shut off engine, wait 5 minutes, and verify oil level is at full mark on dipstick
• Inspect underneath vehicle for any drips or leaks after test drive
• Clear any diagnostic trouble codes if check engine light appeared during procedure

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