This procedure involves removing the engine from the vehicle, disassembling the lower end to access the connecting rods, replacing the connecting rod bearings, and reassembling with precise torque specifications.

Warnings

Tools required

Parts

• Connecting rod bearing set (standard or oversized as measured) × 1 — Use OEM specification
• Engine oil pan gasket × 1 — Use OEM specification
• Timing chain cover gasket × 1 — Use OEM specification
• Valve cover gasket × 1 — Use OEM specification
• Cylinder head gasket × 1 — Use OEM specification
• Engine coolant × 1 — Toyota Super Long Life Coolant (Pink)
• Engine oil filter × 1 — Use OEM specification
• Oil pan drain plug gasket × 1 — Use OEM specification
• Exhaust manifold gaskets × 1 — Use OEM specification
• Engine mount insulators (if damaged) × 1 — Use OEM specification

Fluids

• Toyota Genuine 0W-20 — 5 qt
• Toyota Super Long Life Coolant (Pink) — 10 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect negative battery terminal and wait 90 seconds for airbag system to discharge
3. Remove engine covers and plastic shields from underneath vehicle
4. Drain engine oil completely into appropriate container
5. Drain cooling system by opening radiator petcock and removing lower hose
6. Relieve fuel system pressure by removing fuel pump relay and cranking engine until it stalls
7. Label and photograph all electrical connectors, vacuum lines, and hoses before disconnection
8. Remove hood assembly and store safely (mark hinge positions first)
9. Support vehicle on jack stands at manufacturer-specified lift points

Procedure

1. 1

   Disconnect engine peripherals and accessories
   Disconnect all electrical connectors from engine including injectors, sensors, alternator, and starter. Remove accessory drive belt and serpentine belt tensioner. Disconnect throttle body, intake air tube, and all vacuum lines. Remove alternator and A/C compressor (leave hoses attached and secure compressor to frame). Disconnect power steering pressure switch if equipped. Remove radiator hoses, heater hoses, and transmission cooler lines.
   Torque spec

   Electrical Connector Bolts7 Nm (5 lb-ft)

   Sensor Bolts11 Nm (8 lb-ft)

   Mounting Bolts47 Nm (35 lb-ft)
2. 2

   Separate transmission from engine
   Remove transmission mounting bolts accessible from top. Support transmission with transmission jack. Remove torque converter bolts through starter opening. Mark flexplate-to-torque converter alignment. Remove all bell housing bolts and carefully separate transmission from engine, ensuring torque converter remains with transmission.
3. 3

   Remove engine from vehicle
   Disconnect exhaust manifold from exhaust pipe. Remove engine mount bolts from frame. Attach engine hoist with chains to factory lifting points on engine. Apply slight upward tension and verify all connections are disconnected. Carefully lift engine straight up and forward, clearing transmission input shaft. Transfer engine to engine stand and secure at bell housing bolt locations.
   Torque spec

   Mounting Bolts47 Nm (35 lb-ft)
4. 4

   Remove cylinder head assembly
   Remove valve cover. Remove timing chain cover after removing accessory brackets and crankshaft pulley. Lock timing chain in position with holding tool. Remove timing chain tensioner and guides. Mark timing chain position relative to cam and crank sprockets. Remove camshaft sprockets and timing chain. Remove cylinder head bolts in reverse of tightening sequence (spiral pattern from outside inward). Lift cylinder head assembly off block. Clean all gasket surfaces thoroughly with plastic scraper.
5. 5

   Remove oil pan and oil pump
   Remove all oil pan bolts working from center outward. Carefully separate oil pan from block using plastic pry tool at designated pry points only. Remove oil pickup tube. Remove oil pump mounting bolts and extract oil pump assembly. Clean oil pan and block mating surfaces completely, ensuring no gasket material remains.
   Torque spec

   Gasket Surface Bolts20 Nm (15 lb-ft)
6. 6

   Mark and number connecting rod assemblies
   Rotate crankshaft to position cylinder 1 at bottom dead center. Using permanent marker, mark each connecting rod cap and rod body with cylinder number (1-4) and orientation arrow pointing toward front of engine. Take photos of each rod cap orientation. Number the connecting rod bolts to match their original positions.
   ⚠Rod caps are not interchangeable between cylinders or reversible. Improper installation will cause immediate engine failure.
7. 7

   Remove connecting rod caps and pistons
   Remove connecting rod bolts from cylinder 1 using proper sized socket. Carefully remove rod cap keeping it with its matching rod. Push piston/rod assembly up and out through top of cylinder bore. Place connecting rod cap back on rod and loosely install old bolts to keep them together. Repeat for remaining three cylinders. Inspect each bearing for wear patterns, scoring, or embedded material.
   ⚠Do not allow connecting rod to contact cylinder wall or crankshaft journal during removal to prevent damage.
8. 8

   Measure crankshaft journals and rod bores
   Using micrometer, measure all four connecting rod journals on crankshaft in two directions (perpendicular measurements) to check for out-of-round and taper. Record all measurements. Maximum out-of-round is 0.0008 inches. Measure connecting rod big end bore diameter with dial bore gauge or inside micrometer. Compare measurements to service specifications to determine correct bearing size (standard, 0.25mm undersize, or 0.50mm undersize).
   ℹ️If journals are scored, tapered, or out-of-round beyond specification, crankshaft must be reground and undersize bearings used.
9. 9

   Install new connecting rod bearings and check clearance
   Clean connecting rod and cap bearing bores with clean lint-free cloth and solvent. Install new upper bearing shells into connecting rod bores ensuring tang engages notch. Install lower bearing shells into rod caps. Cut Plastigage to length of bearing width. Place Plastigage strip on crankshaft journal parallel to crankshaft axis. Install rod cap in correct orientation with new bolts. Torque connecting rod bolts to specification: first to 18 lb-ft, then rotate additional 90 degrees using angle gauge. Remove cap carefully without rotating. Compare Plastigage width to scale on package. Clearance should be 0.0008-0.0018 inches. If clearance is incorrect, determine cause and correct before proceeding.
   ⚠Do not rotate crankshaft with Plastigage installed as this will give false readings.
   Torque spec

   Connecting Rod Bolts25 Nm (18 lb-ft) + 90°
10. 10

    Final connecting rod bearing installation
    Remove Plastigage completely from journal and bearing. Apply thin coat of clean engine assembly lube to bearing surfaces and crankshaft journals. Install piston/rod assembly back into correct cylinder bore using piston ring compressor, ensuring directional marks face front of engine. Guide rod onto crankshaft journal carefully avoiding contact with cylinder wall. Install connecting rod cap in marked orientation with new bolts hand-tight. Verify cap alignment marks match. Torque connecting rod bolts using two-stage procedure: Stage 1 to 18 lb-ft (25 Nm), then Stage 2 rotate additional 90 degrees with angle gauge. Repeat for all four connecting rods. Verify each rod moves freely on crankshaft with slight drag from bearing clearance.
    ⚠Rod bolts are torque-to-yield design and must be replaced, never reused.
    Torque spec

    Connecting Rod Bolts25 Nm (18 lb-ft) + 90°
11. 11

    Reinstall oil pump and oil pan
    Install oil pump assembly with new O-ring, ensuring drive gear engages crankshaft properly. Install oil pickup tube with new O-ring. Clean oil pan and block gasket surfaces with brake cleaner. Apply new oil pan gasket or approved RTV sealant per manufacturer specifications. Install oil pan and torque bolts in cross pattern starting from center working outward to specification. Allow RTV to cure per product instructions before adding oil.
    Torque spec

    Gasket Surface Bolts20 Nm (15 lb-ft)

    Gasket Bolts20 Nm (15 lb-ft)
12. 12

    Reinstall cylinder head and timing components
    Position new cylinder head gasket on block ensuring all alignment dowels engage properly. Carefully lower cylinder head onto block. Install cylinder head bolts and torque in specified sequence (spiral pattern from inside outward) per factory specifications. Install timing chain with marks aligned to cam and crank sprocket timing marks. Install chain guides and tensioner. Install camshaft sprockets. Verify timing marks alignment by rotating crankshaft two complete revolutions. Install timing chain cover with new gasket and torque bolts to specification. Install valve cover with new gasket.
    Torque spec

    Gasket Bolts20 Nm (15 lb-ft)

    Cover Bolts16 Nm (12 lb-ft)
13. 13

    Reinstall engine into vehicle
    Attach engine hoist to lifting points and remove engine from stand. Position engine above engine bay and align with transmission bell housing. Lower engine carefully ensuring proper alignment with transmission input shaft and dowel pins. Install engine mount bolts and torque to specification. Reconnect transmission to engine with all bell housing bolts. Install torque converter bolts with marked alignment. Install exhaust manifold connection with new gaskets.
    Torque spec

    Mounting Bolts47 Nm (35 lb-ft)
14. 14

    Reconnect all engine systems
    Reinstall A/C compressor and alternator with mounting bolts torqued to specification. Install accessory drive belt and serpentine belt. Reconnect all electrical connectors to sensors, injectors, alternator, and starter using reference photos. Reconnect throttle body and intake system. Install all vacuum lines. Reconnect coolant hoses, heater hoses, and transmission cooler lines. Install new oil filter. Reinstall hood assembly using marked hinge positions.
    Torque spec

    Mounting Bolts47 Nm (35 lb-ft)

    Electrical Connector Bolts7 Nm (5 lb-ft)
15. 15

    Fill fluids and perform initial start
    Fill engine with 5 quarts of Toyota Genuine 0W-20 engine oil. Fill cooling system with Toyota Super Long Life Coolant (Pink) mixed 50/50 with distilled water (10 quarts total capacity). Reconnect negative battery terminal. Verify all tools and parts are clear of engine. Prime fuel system by cycling ignition on/off three times without cranking. Start engine and immediately verify oil pressure light extinguishes. Allow engine to idle and monitor for leaks, unusual noises, or warning lights. Check coolant level after engine reaches operating temperature and burp cooling system.

Reassembly

1. All fasteners must be torqued to specification using calibrated torque wrench
2. Connecting rod bolts are torque-to-yield and must never be reused
3. Always verify timing chain alignment after installation and after two full crankshaft rotations
4. Use only specified Toyota fluids - mixing coolant types can cause system damage
5. Allow RTV sealant to cure fully before filling with fluids or starting engine

Verification

• Oil pressure should register within 5 seconds of starting and maintain normal pressure at idle
• No coolant, oil, or fuel leaks visible after engine reaches operating temperature
• Engine should idle smoothly without unusual noises, vibration, or knocking sounds
• All warning lights should extinguish after initial start (check engine, oil pressure, coolant temperature)
• Perform test drive and verify normal acceleration, no misfire, and proper transmission engagement
• After 50 miles, re-check oil level and inspect for any new leaks
• Consider oil analysis after 500 miles to verify bearing wear-in is normal

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