This procedure covers replacement of connecting rod bearings on the 2AR-FE 2.5L I4 engine, requiring complete engine disassembly including removal from vehicle, crankshaft extraction, and precision reassembly.

Warnings

Tools required

Parts

• Connecting rod bearing set (STD or appropriate oversize) × 1 — Use OEM specification
• Engine oil filter × 1 — 90915-YZZF2
• Oil pan gasket × 1 — Use OEM specification
• Timing chain cover gasket × 1 — Use OEM specification
• Valve cover gasket × 1 — Use OEM specification
• Valve cover grommets and seals × 1 — Use OEM specification
• Water pump O-ring × 1 — Use OEM specification
• Coolant drain plug gasket × 1 — Use OEM specification
• RTV silicone sealant (Toyota Genuine) × 1 — 08826-00080
• Engine assembly lube × 1 — Use OEM specification

Fluids

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

Preparation

1. Park vehicle on level surface and apply parking brake. Chock rear wheels securely.
2. Disconnect negative battery terminal and isolate cable away from battery.
3. Drain engine oil completely and remove oil filter.
4. Drain engine coolant from radiator and engine block drain plugs.
5. Remove engine cover and air intake assembly.
6. Relieve fuel system pressure by removing fuel pump relay and cranking engine until it stops.
7. Label and photograph all electrical connectors, vacuum lines, and hose routing before disconnection.
8. Support transaxle with suitable jack before removing engine mounts.

Procedure

1. 1

   Remove engine from vehicle
   Disconnect all electrical connectors, coolant hoses, fuel lines, exhaust manifold, and accessory drive components. Remove radiator if necessary for clearance. Attach engine hoist to factory lifting points and support engine weight. Remove engine mounting bolts and carefully lift engine from engine bay while guiding transaxle separation. Mount engine securely on engine stand.
   Torque spec

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

   Remove external engine components
   Remove alternator, A/C compressor (if attached), power steering pump, and all accessory brackets. Remove throttle body, intake manifold, exhaust manifold, and fuel rail assembly. Remove ignition coils and spark plugs. Remove valve cover after removing all bolts and harness clips. Label all components for reassembly.
   Torque spec

   Cover Bolts16 Nm (12 lb-ft)
3. 3

   Remove timing chain and oil pump
   Rotate crankshaft to TDC on cylinder #1 (timing marks aligned). Remove crankshaft pulley bolt using appropriate holding tool. Remove timing chain cover, timing chain tensioner, timing chain guides, and timing chain. Remove variable valve timing (VVT) gears from camshafts. Remove oil pump assembly from front of engine block.
4. 4

   Remove cylinder head
   Remove cylinder head bolts in reverse of tightening sequence (start from outer bolts working inward in multiple passes). Carefully lift cylinder head from block, breaking gasket seal with plastic pry tool if necessary. Place cylinder head on clean padded surface. Remove and discard cylinder head gasket. Cover cylinder bores with clean shop towels to prevent debris entry.
5. 5

   Remove oil pan and oil pickup tube
   Remove all oil pan bolts and carefully separate pan from block using plastic pry tool at designated pry points. Clean all old gasket material and RTV from both mating surfaces. Remove oil pickup tube and strainer assembly from block. Inspect oil pickup screen for debris that may indicate bearing failure.
   ⚠If metal debris is found in oil pan or pickup screen, all engine bearings must be inspected and likely replaced including main bearings.
   Torque spec

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

   Remove ridge from cylinder bores
   Using ridge reamer, carefully remove any ridge at top of each cylinder bore where piston ring travel ends. This prevents ring damage during piston removal. Work carefully to avoid removing material from cylinder wall below ridge. Clean all cutting debris from bores with lint-free cloth and oil.
7. 7

   Mark and remove connecting rod caps
   Use permanent marker or stamps to clearly mark each connecting rod and cap with cylinder number and orientation (mark front of engine). Marks must be on same side of rod and cap. Remove connecting rod bolts from all four cylinders. Carefully remove rod caps and bearing shells, keeping each cap with its corresponding rod. Inspect bearing shells for wear patterns, scoring, or embedded material.
   ⚠Rod caps must be reinstalled in exact original position and orientation. Mixing caps will cause catastrophic engine failure.
   Torque spec

   Connecting Rod Bolts25 Nm (18 lb-ft) + 90°
8. 8

   Remove pistons and connecting rods
   Push each piston and rod assembly up and out through top of cylinder bore. Protect crankshaft journals by sliding short pieces of fuel hose over rod bolts before removal. Remove upper bearing shell from each rod. Keep all components organized by cylinder number. Install rod caps back on rods with bearing shells to prevent mixing.
9. 9

   Measure crankshaft journal diameter
   Using precision micrometer, measure diameter of each connecting rod journal in multiple orientations (90 degrees apart) and positions along journal length. Record all measurements. Journals must be within 47.988-48.000mm (1.8893-1.8898 inches). Out-of-round limit is 0.013mm (0.0005 inch). Taper limit is 0.013mm (0.0005 inch). Journals exceeding these limits require crankshaft grinding and undersized bearings.
   ⚠Crankshaft journals must be within specification. Installing new bearings on worn journals will result in rapid bearing failure.
10. 10

    Inspect connecting rods and measure bore
    Inspect connecting rods for cracks, especially around bolt holes and beam area. Using dial bore gauge with rod caps torqued to specification (without bearings), measure big end bore diameter. Standard bore is 51.006-51.019mm (2.0081-2.0086 inches). Out-of-round limit is 0.025mm (0.001 inch). Rods exceeding limits must be replaced.
    Torque spec

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

    Clean all components thoroughly
    Clean crankshaft journals with lint-free cloth and lacquer thinner or brake cleaner. Ensure oil passages in crankshaft are completely clear using pipe cleaners or appropriate cleaning tools. Clean connecting rod bores and cap mating surfaces. Remove all debris, old gasket material, and carbon deposits from block deck surface. Blow out all oil passages with compressed air while wearing safety glasses.
12. 12

    Install new connecting rod bearings
    Install new upper bearing shells into connecting rods, ensuring locating tabs engage slots in rods. Install new lower bearing shells into rod caps with tabs properly engaged. Bearings should snap into place and sit flush. Do NOT file bearings or caps. Apply assembly lube generously to all bearing surfaces and crankshaft journals. Lubricate cylinder walls with clean engine oil.
    ⚠Bearing shells must be installed dry - do not oil the back of bearings. Oil only the bearing surface that contacts the crankshaft.
13. 13

    Check bearing clearance with Plastigage
    Place strip of Plastigage lengthwise on each crankshaft journal. Install rod caps with bearings (dry - no oil) and torque bolts to 25 Nm (18 lb-ft) only - do NOT add the 90-degree rotation yet. Remove caps carefully without rotating and measure flattened Plastigage width using package scale. Clearance should be 0.025-0.058mm (0.001-0.0023 inches). Service limit is 0.08mm (0.003 inches).
    ⚠If clearance exceeds specification, verify bearing part number and journal diameter. Never install bearings with excessive clearance.
14. 14

    Install piston and rod assemblies
    Remove old Plastigage completely and re-lubricate bearings and journals with assembly lube. Compress piston rings using ring compressor tool. Ensure piston orientation mark (front mark) faces timing chain side of engine. Guide rod bolts with hose protectors over journals. Gently tap piston into bore with hammer handle until seated. Remove hose protectors.
15. 15

    Install and torque connecting rod caps
    Install each rod cap in correct position with cylinder number marks aligned. Install new connecting rod bolts if required (recommended). Lubricate bolt threads and underside of bolt heads with clean engine oil. Torque bolts in two stages: First, torque to 25 Nm (18 lb-ft). Second, rotate each bolt an additional 90 degrees using angle gauge. Verify marks remain aligned after torquing. Rotate crankshaft two full revolutions by hand to verify smooth rotation with no binding.
    ⚠Connecting rod bolts use torque-to-yield method. Bolts must be torqued in exact sequence: initial torque, then angle rotation. Do not skip angle rotation step.
    Torque spec

    Connecting Rod Bolts25 Nm (18 lb-ft) + 90°
16. 16

    Reinstall oil pump and timing components
    Install oil pickup tube and strainer with new O-ring. Apply thin bead of RTV to oil pan mating surface and install pan with new gasket. Torque oil pan bolts to specification. Install oil pump assembly to block. Install timing chain with alignment marks properly positioned (crankshaft and camshaft timing marks aligned per factory specification). Install chain guides, tensioner, and VVT gears. Verify timing mark alignment.
    Torque spec

    Gasket Bolts20 Nm (15 lb-ft)
17. 17

    Install cylinder head and external components
    Install new cylinder head gasket with proper orientation (TOP mark facing up). Carefully lower cylinder head onto block, ensuring dowel pins engage. Install cylinder head bolts and torque in proper sequence per factory specification (center outward in multiple passes). Install timing chain cover with new gasket and torque bolts. Reinstall valve cover with new gasket. Reinstall all external components, intake manifold, exhaust manifold, and accessories in reverse order of removal.
    Torque spec

    Cover Bolts16 Nm (12 lb-ft)
18. 18

    Reinstall engine in vehicle
    Remove engine from stand and attach to engine hoist. Carefully lower engine into engine bay while aligning with transaxle. Install engine mounting bolts and torque to specification. Reconnect all electrical connectors, fuel lines, coolant hoses, exhaust system, and accessory drive components. Reinstall radiator if removed. Double-check all connections against photos taken during disassembly.
    Torque spec

    Mounting Bolts47 Nm (35 lb-ft)
19. 19

    Fill fluids and perform initial start
    Install new oil filter and fill engine with 5 quarts of Toyota Genuine 0W-20 oil. Refill cooling system with Toyota Super Long Life Coolant (Pink) - approximately 10 quarts total. Reconnect battery. Prime fuel system by cycling ignition on/off three times without starting. Start engine and verify oil pressure light extinguishes immediately. Monitor for leaks, unusual noises, or vibration. Allow engine to reach operating temperature while monitoring coolant level.
    ⚠️If oil pressure warning light does not extinguish within 2-3 seconds of starting, immediately shut off engine and investigate. Running engine without oil pressure will destroy new bearings.

Reassembly

1. All fasteners with torque-to-yield specifications require new bolts - do not reuse connecting rod bolts if they have been previously torqued past yield point
2. Apply RTV sealant to oil pan and timing cover mating surfaces in continuous 2-3mm bead, avoiding oil passages
3. Timing chain alignment is critical - verify all timing marks align at TDC on cylinder #1 before finalizing timing cover installation
4. Torque all bolts in multiple progressive steps when sequence is specified, working from center outward
5. Ensure all electrical connectors click fully into place and harness clips are secured properly

Verification

• Start engine and verify oil pressure warning light extinguishes within 2-3 seconds
• Listen for abnormal noises including knocking, ticking, or rattling that would indicate bearing problems
• Monitor for oil, coolant, or fuel leaks around all disturbed components during initial running period
• Verify engine runs smoothly with no misfires or rough idle conditions
• After initial warm-up cycle, allow engine to cool and recheck oil level - top off if necessary
• Bleed cooling system completely to remove all air pockets
• Road test vehicle under light load initially, gradually increasing to verify proper operation under all conditions
• Recheck oil level and inspect for leaks after first 50-100 miles of operation
• Monitor oil pressure with mechanical gauge if possible - should read 4.3-14 psi at idle (hot), 36-71 psi at 3000 RPM

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