Replace connecting rod bearings on the 3.5L EcoBoost V6 engine, requiring complete engine removal, disassembly, bearing replacement, and reinstallation with precision torque procedures.

Warnings

Tools required

Parts

• Connecting rod bearing set (standard or oversized as measured) × 1 — Motorcraft or OEM equivalent, sized to crankshaft
• Connecting rod bolts (complete set) × 12 — Use OEM specification - torque-to-yield bolts
• Engine oil and filter × 1 — FL-910S or equivalent
• Oil pan gasket × 1 — Use OEM specification
• Valve cover gaskets (both) × 2 — Use OEM specification
• Intake manifold gaskets × 1 — Use OEM specification
• Exhaust manifold gaskets (both turbo flanges) × 2 — Use OEM specification
• Coolant × 1 — Motorcraft Orange Coolant
• Various engine seals and O-rings × 1 — Timing cover, oil pump, etc.
• RTV silicone gasket maker × 1 — Motorcraft TA-30 or equivalent

Fluids

• Motorcraft 5W-20 Synthetic Blend — 6 qt
• Motorcraft Orange Coolant — 13 qt

Preparation

1. Park vehicle on level ground and engage parking brake. Place wheel chocks at rear wheels.
2. Disconnect negative battery cable and wait 10 minutes for airbag system to discharge.
3. Relieve fuel system pressure by removing fuel pump fuse and running engine until it stalls.
4. Drain engine coolant completely into suitable containers.
5. Drain engine oil and remove oil filter.
6. Drain transfer case and front differential if removing engine from below.
7. Remove engine cover and air intake system completely.
8. Document all electrical connector positions with photos before disconnection.
9. Have fire extinguisher readily available when working around fuel system.

Procedure

1. 1

   Remove Engine from Vehicle
   Remove hood, radiator, cooling fans, and all coolant hoses. Disconnect all electrical connectors including PCM, alternator, and sensors. Disconnect both turbocharger inlet and outlet pipes. Remove both exhaust manifolds/turbochargers as assemblies. Disconnect fuel lines at fuel rail. Disconnect throttle body and all vacuum lines. Remove transmission bell housing bolts. Support transmission with jack. Attach engine hoist with chains to factory lift points. Remove engine mount bolts and carefully lift engine from vehicle, tilting as necessary to clear firewall and frame.
2. 2

   Mount Engine to Stand and External Component Removal
   Secure engine to engine stand using transmission bell housing bolt holes. Remove remaining accessories: alternator, A/C compressor, power steering pump, starter motor, and all wiring harnesses. Remove intake manifold completely. Remove both valve covers. Remove timing chains, guides, and tensioners following timing chain procedure. Remove oil pan and oil pump assembly. Remove front timing cover.
3. 3

   Inspect and Measure Crankshaft
   Rotate engine so crankshaft is accessible. Clean all rod journals thoroughly with lint-free cloth and solvent. Using precision micrometers, measure each of the six crankshaft rod journals in at least four locations (90° apart) and check for taper and out-of-round condition. Record all measurements. Maximum out-of-round is 0.0002 inches. Maximum taper is 0.0002 inches. Inspect journals for scoring, heat discoloration, or damage. If journals are damaged or out of specification, crankshaft must be machined and oversized bearings used.
4. 4

   Remove Pistons and Connecting Rod Assemblies
   Mark each connecting rod cap and rod body with cylinder number (1-6) using permanent marker or stamps - marks must match and face the same direction. Note that cylinders are numbered with 1-3 on passenger side (right bank) and 4-6 on driver side (left bank) from front to rear. Remove connecting rod cap bolts from all six cylinders and carefully remove caps, keeping each cap with its matching rod. Push each piston/connecting rod assembly up and out through the top of the cylinder bore. Place each assembly in numbered order to maintain original cylinder position. Inspect each piston for damage.
5. 5

   Remove Old Bearings and Clean Components
   Remove old bearing inserts from all connecting rods and caps. Note the tang position on each bearing - upper and lower bearings may be different. Thoroughly clean all connecting rods and caps with solvent. Clean bearing journals on crankshaft again. Inspect connecting rod big end bores for cracks using magnification. Check connecting rods for straightness and twist using rod alignment fixture if available - replacement required if bent. Clean all rod bolt holes and cap mating surfaces. Use compressed air to blow out all oil passages.
6. 6

   Measure Bearing Clearances with Plastigage
   Install new upper bearing shells into connecting rods, ensuring tang engages slot. Install new lower bearing shells into caps. Place connecting rod assemblies back onto crankshaft journals in correct cylinder positions. Cut strips of Plastigage and place on each crankshaft journal across the width of the bearing. Install connecting rod caps in correct orientation with match marks aligned. Install NEW connecting rod bolts finger tight only. Torque bolts ONLY to initial 18 lb-ft specification - do NOT apply angle torque yet. Do not rotate crankshaft with Plastigage installed. Carefully remove caps and measure flattened Plastigage width using gauge on package. Compare to specifications: standard clearance is 0.0009-0.0019 inches. If clearance is too tight, undersize bearings required. If clearance is too loose, oversized bearings or crankshaft machining required.
   Torque spec

   Connecting Rod Bolts25 Nm (18 lb-ft) + 90°
7. 7

   Final Bearing Installation
   Once correct bearing size is determined and clearances verified, remove all Plastigage residue completely. Lubricate all bearing surfaces with fresh engine assembly lube or clean engine oil. Coat crankshaft journals with assembly lube. Install upper bearing shells into connecting rods with tangs properly seated. Install lower bearing shells into caps with tangs properly seated. Carefully install connecting rod assemblies onto crankshaft journals in correct numbered positions, ensuring any directional markings face forward.
8. 8

   Torque Connecting Rod Bolts - Critical Multi-Step Process
   This is the most critical step. Install NEW connecting rod bolts into each rod cap - never reuse old bolts. Install caps in correct orientation with match marks aligned. Using precision torque wrench, torque all connecting rod bolts to Step 1: 18 lb-ft in a criss-cross pattern. Then torque all bolts to Step 2: 33 lb-ft. Finally, using torque angle gauge, rotate each bolt an additional 90 degrees for Step 3. Verify each bolt has been properly torqued through all three steps. After torquing, rotate crankshaft by hand two complete revolutions to verify smooth rotation with no binding. Any binding indicates incorrect assembly or bearing failure - disassemble and inspect immediately.
   Torque spec

   Connecting Rod Bolts25 Nm (18 lb-ft) + 90°
9. 9

   Install Pistons into Cylinders
   Ensure piston rings are properly gapped and installed on pistons in correct orientation. Install ring compressor on each piston. Lubricate cylinder walls with engine oil. Carefully install each piston/connecting rod assembly into its original cylinder bore, ensuring any directional marks on piston face forward (toward front of engine). Tap piston gently through ring compressor into bore using wooden hammer handle. Guide connecting rod onto crankshaft journal as piston enters cylinder. Repeat for all six cylinders.
10. 10

    Verify Assembly and Install Oil System
    Rotate crankshaft multiple complete revolutions by hand to verify smooth operation. Check that all pistons move freely through complete stroke. Install oil pump using new gasket or O-ring. Install oil pan with new gasket, ensuring proper RTV application at corners where gasket meets timing cover. Install oil pan bolts to specification. Prime oil system by rotating oil pump with drill motor adapter before installing timing components.
11. 11

    Reinstall Timing Components
    Install timing chains, guides, tensioners, and sprockets according to timing chain installation procedure, ensuring all timing marks are properly aligned. Install front timing cover with new gasket and seals. Rotate engine two complete revolutions and recheck all timing marks to confirm correct installation.
12. 12

    Reinstall Cylinder Heads Components and External Accessories
    Install intake manifold with new gaskets. Install valve covers with new gaskets. Reinstall all external accessories in reverse order of removal: alternator, A/C compressor, power steering pump, starter. Reconnect all sensors with new O-rings where applicable. Install exhaust manifolds/turbochargers with new gaskets.
    Torque spec

    Gasket Bolts23 Nm (17 lb-ft)

    Sensor Bolts12 Nm (9 lb-ft)
13. 13

    Reinstall Engine into Vehicle
    Using engine hoist, carefully lower engine into engine bay, aligning with transmission bell housing and engine mounts. Install engine mounting bolts. Remove engine hoist. Reconnect transmission bell housing bolts. Reconnect all electrical connectors, fuel lines, coolant hoses, and vacuum lines. Install turbocharger inlet and outlet piping. Install radiator, cooling fans, and all cooling system components. Install air intake system and engine cover.
    Torque spec

    Mounting Bolts55 Nm (40 lb-ft)
14. 14

    Fill Fluids and Initial Start
    Install new oil filter and fill engine with 6 quarts of Motorcraft 5W-20 synthetic blend oil. Fill cooling system with 13 quarts of Motorcraft Orange coolant and bleed air from system. Refill transfer case and front differential to proper levels. Reconnect negative battery cable. Before starting, turn ignition to ON position (not start) and listen for fuel pump operation. Check for fuel leaks. Perform initial start and allow engine to idle. Monitor oil pressure immediately - should show pressure within 5 seconds. Check for any leaks at oil pan, valve covers, and all connections.

Reassembly

1. All gaskets, seals, and connecting rod bolts MUST be replaced with new components.
2. Connecting rod caps must be installed in exact original position with match marks aligned.
3. Follow the three-step torque procedure exactly as specified: 18 lb-ft, then 33 lb-ft, then +90 degrees.
4. Crankshaft must rotate freely by hand after connecting rod installation - any binding requires immediate disassembly.
5. Prime oil system before initial start to prevent dry start condition.

Verification

• Start engine and verify oil pressure builds immediately (within 5 seconds of starting).
• Listen for any abnormal engine noises such as knocking, rattling, or tapping that could indicate bearing problems.
• Check for oil leaks at oil pan gasket, valve covers, and timing cover after engine reaches operating temperature.
• Allow engine to reach full operating temperature and verify cooling system operates normally.
• Perform test drive and monitor engine performance, listening for any unusual sounds under load.
• After initial drive cycle, re-check oil level and inspect for any new leaks.
• Monitor oil pressure gauge during driving - pressure should remain stable and within normal range.
• Consider performing oil analysis after 500 miles to verify bearing material is not present in oil.

More procedures for this vehicle