Complete removal and replacement of all six pistons in the 3.5L EcoBoost V6 engine, requiring engine removal and complete disassembly of the short block.

Warnings

Tools required

Parts

• Pistons (set of 6) × 1 — Use OEM specification
• Piston rings (set of 6) × 1 — Use OEM specification
• Piston pins (wrist pins) × 6 — Use OEM specification
• Piston pin retaining clips × 12 — Use OEM specification
• Connecting rod bolts × 12 — Use OEM TTY bolts
• Main bearing cap bolts × 1 — Use OEM TTY bolts
• Cylinder head gaskets × 2 — Use OEM specification
• Cylinder head bolts × 1 — Use OEM TTY bolts
• Oil pan gasket × 1 — Use OEM specification
• Valve cover gaskets × 2 — Use OEM specification
• Timing chain cover gasket × 1 — Use OEM specification
• Timing chains × 2 — Use OEM specification
• Timing chain guides and tensioners × 1 — Use OEM specification
• Intake manifold gaskets × 1 — Use OEM specification
• Exhaust manifold gaskets × 2 — Use OEM specification
• Turbocharger gaskets × 1 — Use OEM specification
• Oil drain plug crush washer × 1 — Use OEM specification
• Engine oil filter × 1 — FL-820S or equivalent
• RTV silicone sealant × 1 — Motorcraft TA-357 or equivalent

Fluids

• Motorcraft 5W-20 Synthetic Blend — 6 qt
• Motorcraft Orange Coolant — 13 qt
• Motorcraft MERCON LV ATF — 11 qt
• Motorcraft Transfer Case Fluid — 2.5 qt
• 75W-90 GL-5 Gear Oil (front diff) — 1.5 qt
• Motorcraft 75W-140 Synthetic Gear Oil (rear diff) — 2 qt

Preparation

1. Disconnect negative battery cable and isolate
2. Relieve fuel system pressure by removing fuel pump fuse and running engine until it stalls
3. Raise vehicle on lift or support securely on jack stands at all four corners
4. Drain engine oil, coolant, transmission fluid, and transfer case fluid into appropriate containers
5. Remove engine cover and air intake system completely
6. Remove both turbochargers and charge air coolers
7. Remove front skid plate and front differential if equipped
8. Support transmission with jack and remove bell housing bolts
9. Disconnect all wiring harnesses, hoses, and fuel lines from engine
10. Remove radiator, cooling fans, and AC condenser
11. Attach engine hoist to factory lifting points and remove engine mount bolts
12. Carefully lift engine from vehicle and mount securely on engine stand

Procedure

1. 1

   Remove external engine components
   Remove alternator, AC compressor (leave hoses attached and secure aside), power steering pump, water pump, and all accessory brackets. Remove both valve covers, intake manifolds (upper and lower), and exhaust manifolds. Label and store all bolts systematically.
2. 2

   Remove timing components
   Rotate engine to TDC on cylinder #1. Mark timing chain positions on all sprockets. Remove timing chain cover. Remove primary and secondary timing chains, guides, and tensioners. Remove camshafts from both cylinder heads. Keep all components organized by bank.
   ⚠Take detailed photos of timing chain routing and cam phaser positions before removal. EcoBoost timing is complex with variable cam timing.
3. 3

   Remove cylinder heads
   Loosen cylinder head bolts in reverse of tightening sequence (consult service manual for pattern). Remove both cylinder heads and place on clean protected surface. Inspect head surfaces for warping or damage. Remove and discard head gaskets.
   Torque spec

   Cylinder Head Bolts65 Nm (48 lb-ft)
4. 4

   Remove oil pan and pickup tube
   Remove all oil pan bolts in sequence from outside to inside. Carefully separate oil pan from block using plastic pry tools only. Remove oil pump pickup tube mounting bolts and remove tube. Inspect oil pump for damage or wear.
   ⚠Do not pry between oil pan and block mating surfaces. Use designated pry points only to avoid damage.
   Torque spec

   Oil Pan Bolts12 Nm (9 lb-ft)

   Oil Pump Pickup Tube12 Nm (9 lb-ft)
5. 5

   Inspect and measure cylinder bores
   Use cylinder ridge reamer to remove any ridge at top of each cylinder bore. Measure each cylinder bore diameter at top, middle, and bottom in two perpendicular directions. Record all measurements. Check for taper (max 0.05mm) and out-of-round (max 0.025mm). Cylinders exceeding specifications require machining.
   ⚠Ridge reaming must be done carefully to avoid cutting into cylinder wall below ridge. Follow reamer manufacturer instructions exactly.
6. 6

   Remove pistons and connecting rods
   Rotate crankshaft to position cylinders for access. Mark each connecting rod and cap with cylinder number and orientation (mark faces adjacent to each other). Remove connecting rod cap bolts and caps. Push each piston/rod assembly up through top of block. Keep all components organized by cylinder number.
   ⚠Never reuse connecting rod bolts - these are TTY and must be replaced. Do not mix rod caps between cylinders.
   Torque spec

   Connecting Rod Bolts45 Nm (33 lb-ft)
7. 7

   Disassemble pistons from connecting rods
   Remove piston pin retaining clips using appropriate tool. Press or tap out piston pins to separate pistons from connecting rods. Remove old piston rings using ring removal tool. Clean all carbon deposits from piston ring grooves and oil return holes. Inspect connecting rods for bends, twists, or damage.
   ℹ️Connecting rods should be checked for straightness and parallel on specialized equipment if damage is suspected.
8. 8

   Prepare cylinder bores
   Clean all cylinder bores thoroughly with solvent and lint-free cloths. Hone each cylinder bore using 280-320 grit stones to create proper crosshatch pattern (45-60 degree angle). Wash cylinders again with hot soapy water, then dry and coat with clean engine oil immediately to prevent rust.
   ⚠Proper crosshatch pattern is critical for ring seating. Hone until consistent pattern is achieved in all cylinders.
9. 9

   Install piston rings on new pistons
   Using ring installation tool, install oil control ring expander first, then oil control ring rails. Install second compression ring with marking facing up. Install top compression ring with marking facing up. Verify ring end gaps are within specification (0.25-0.45mm for compression rings, 0.25-0.75mm for oil rings). Stagger ring gaps 120 degrees apart.
   ⚠Piston rings are fragile and can break if over-expanded. Use proper ring installation tool and follow manufacturer instructions.
10. 10

    Assemble pistons to connecting rods
    Install new piston pins to attach each piston to its corresponding connecting rod. Ensure piston orientation matches factory markings (front mark toward front of engine). Install new piston pin retaining clips, ensuring they are fully seated in grooves. Verify pins rotate smoothly but without excessive play.
    ⚠Piston pin retaining clips must be fully seated. A loose clip can fall into engine causing catastrophic damage.
11. 11

    Install piston and rod assemblies
    Coat cylinder bores, piston rings, and rod bearings with assembly lube. Install rod bearings in connecting rods ensuring tangs are properly seated. Position ring gaps per specification. Use ring compressor to compress rings and carefully tap each piston into its cylinder from top of block. Ensure rod orientation mark faces correct direction. Install rod caps with new bolts finger tight.
    ⚠Never force pistons into bores. Rings must be fully compressed and properly aligned. Forcing can break rings or damage pistons.
12. 12

    Check bearing clearances and torque connecting rods
    Place Plastigage on each rod journal. Install rod caps and torque NEW bolts to 33 lb-ft (45 Nm), then rotate additional 90 degrees. Remove caps and measure Plastigage width to verify bearing clearance is within 0.025-0.060mm specification. If clearances are correct, apply final torque to all rod bolts: 33 lb-ft (45 Nm) plus 90 degrees angle.
    ⚠️Connecting rod bolts are torque-to-yield. After checking clearances, remove bolts and install NEW bolts for final assembly.
    Torque spec

    Connecting Rod Bolts45 Nm (33 lb-ft)
13. 13

    Install oil pump pickup and oil pan
    Install oil pump pickup tube with new O-ring and torque mounting bolts to 9 lb-ft (12 Nm). Clean all oil pan mating surfaces thoroughly. Apply RTV silicone sealant to corners where front cover and rear seal retainer meet block. Install new oil pan gasket and position oil pan. Install oil pan bolts and torque to 9 lb-ft (12 Nm) in sequence from center outward.
    ℹ️Oil pan must be installed within 10 minutes of applying RTV sealant. Allow 1 hour cure time before filling with oil.
    Torque spec

    Oil Pump Pickup Tube12 Nm (9 lb-ft)

    Oil Pan Bolts12 Nm (9 lb-ft)
14. 14

    Install cylinder heads
    Clean all head and block mating surfaces. Install new head gaskets ensuring alignment dowels are properly seated. Position cylinder heads on block. Install NEW cylinder head bolts and hand tighten. Following factory torque sequence, torque all head bolts to 48 lb-ft (65 Nm), then rotate all bolts 90 degrees, then rotate all bolts an additional 90 degrees (total 180 degrees turn).
    ⚠️Cylinder head bolts are TTY and must be replaced. Follow exact torque sequence from service manual. Incorrect sequence or reused bolts will cause head gasket failure.
    Torque spec

    Cylinder Head Bolts65 Nm (48 lb-ft)
15. 15

    Install timing components and reassemble engine
    Install camshafts with proper timing alignment. Install primary and secondary timing chains per factory timing marks and procedures. Install timing chain cover with new gasket. Install all external components in reverse order of removal including intake manifolds, exhaust manifolds, valve covers, and accessories. Torque all fasteners to specification.

Reassembly

1. Install engine into vehicle using hoist, aligning with transmission and motor mounts
2. Reconnect all wiring harnesses, fuel lines, and cooling system hoses
3. Install turbochargers with new gaskets, torque all mounting hardware to specification
4. Reinstall radiator, AC condenser, and cooling fans
5. Reconnect exhaust system with new gaskets at turbocharger flanges
6. Install engine covers and air intake system
7. Fill engine with specified 6 quarts of Motorcraft 5W-20 synthetic blend oil
8. Fill cooling system with 13 quarts Motorcraft Orange coolant and bleed air
9. Refill transmission, transfer case, and differentials with specified fluids
10. Install new engine oil filter and drain plug with new crush washer, torque drain plug to 26 lb-ft (35 Nm)
11. Double-check all connections, torques, and fluid levels before starting

Verification

• Verify all fluid levels are correct and no leaks are present
• Reconnect battery and perform key-on engine-off checks for warning lights
• Prime oil system by cranking engine without starting (disable ignition/fuel)
• Start engine and verify oil pressure within 5 seconds
• Allow engine to warm to operating temperature and check for leaks
• Monitor engine for unusual noises, vibrations, or warning lights
• Perform multiple cold starts over several days to ensure proper ring seating
• Change oil and filter after 500 miles of break-in driving
• Avoid extended high RPM operation for first 1000 miles to allow proper ring seating
• Scan for diagnostic trouble codes and verify all systems operating normally

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