This procedure involves complete engine disassembly to replace all piston rings on the 3.5L EcoBoost V6, including removal of cylinder heads, oil pan, and crankshaft components.

Warnings

Tools required

Parts

• Piston ring set (all 6 cylinders) × 1 — Use OEM Ford specification for 3.5L EcoBoost
• Cylinder head gasket set × 2 — Use OEM specification
• Oil pan gasket × 1 — Use OEM specification
• Valve cover gaskets × 2 — Use OEM specification
• Timing chain cover gasket × 1 — Use OEM specification
• Oil filter × 1 — FL-820S or equivalent
• Oil drain plug crush washer × 1 — Use OEM specification
• Connecting rod bolt set × 1 — TTY bolts - replace with OEM
• Cylinder head bolt set × 2 — TTY bolts - replace with OEM
• Main bearing cap bolt set × 1 — TTY bolts - replace with OEM
• Turbocharger gaskets and seals × 1 — Use OEM specification
• Exhaust manifold gaskets × 2 — Use OEM specification
• Intake manifold gaskets × 1 — Use OEM specification
• RTV silicone sealant × 2 — Motorcraft TA-31

Fluids

• Motorcraft 5W-20 Synthetic Blend — 6 qt
• Motorcraft Orange Coolant — 13 qt
• Assembly lube — 0.5 qt

Preparation

1. Disconnect negative battery cable and isolate
2. Drain engine coolant completely into suitable container
3. Drain engine oil and remove oil filter
4. Remove front bumper cover and grille assembly for access
5. Remove intercooler and charge air cooler piping
6. Disconnect all electrical connectors from engine and label for reinstallation
7. Remove air intake system and air filter housing
8. Disconnect fuel lines at fuel rail using proper disconnect tools (relieve fuel pressure first)
9. Remove accessory drive belt and tensioner
10. Raise vehicle and secure on jack stands, remove front wheels
11. Drain transfer case and front differential if removing engine from above
12. Disconnect exhaust system at manifolds
13. Remove radiator and cooling fans
14. Disconnect transmission cooler lines and label
15. Support transmission with transmission jack
16. Prepare clean workspace and engine stand for disassembly

Procedure

1. 1

   Remove engine from vehicle
   Disconnect remaining engine mounts, transmission bellhousing bolts, and all remaining connections. Attach engine hoist to factory lift points on engine. Carefully lift engine forward and up out of engine bay, separating from transmission. Transfer engine to engine stand and secure properly. Verify engine is stable on stand before proceeding.
2. 2

   Remove external components and accessories
   Remove both turbochargers and all exhaust manifolds. Remove intake manifold assembly. Remove fuel rails and injectors as complete assembly. Remove both valve covers. Remove alternator, A/C compressor, and power steering pump. Remove water pump and thermostat housing. Remove all remaining sensors and wiring harnesses from engine block.
   ⚠Keep fuel injectors protected and covered to prevent contamination. Do not allow injector tips to contact any surface.
3. 3

   Remove timing components
   Rotate engine to TDC on cylinder #1. Mark timing chain positions relative to camshaft and crankshaft gears. Remove timing chain cover. Remove timing chains, guides, and tensioners keeping left and right bank components separate. Remove camshaft phaser bolts and remove camshafts from both cylinder heads. Store camshafts in order and orientation for reinstallation.
   ⚠Camshaft journals and lobes are extremely sensitive to damage. Support camshafts properly and never place directly on hard surfaces.
   Torque spec

   Cover Bolts19 Nm (14 lb-ft)
4. 4

   Remove cylinder heads
   Remove cylinder head bolts in reverse of tightening sequence (consult service manual for exact sequence). Carefully lift cylinder heads off engine block. Place heads on wood blocks, combustion chamber side up. Inspect head gasket surfaces and combustion chambers for signs of damage or pre-existing issues.
   ℹ️Cylinder head bolts are TTY and will be replaced. Do not attempt to reuse.
5. 5

   Remove oil pan and pickup tube
   Remove oil pan bolts in reverse sequence. Carefully separate oil pan from block using plastic wedge if necessary. Remove oil pump pickup tube and O-ring. Clean all oil pan gasket surfaces thoroughly. Inspect oil pickup screen for debris.
   Torque spec

   Oil Pan Bolts12 Nm (9 lb-ft)

   Oil Pump Pickup Tube12 Nm (9 lb-ft)
6. 6

   Remove crankshaft and main bearing caps
   Mark main bearing caps for position and orientation. Remove main bearing cap bolts in reverse sequence (outer bolts first, then inner). Carefully remove main bearing caps and set aside in order. Lift crankshaft out of engine block and place on protected surface. Remove main bearing inserts and keep with respective caps.
   ⚠Main bearing cap bolts are TTY and must be replaced. Crankshaft weighs approximately 50 lbs - use care when lifting.
7. 7

   Remove pistons and connecting rods
   Mark each connecting rod and cap with cylinder number and orientation (mark facing front). Remove connecting rod bolts. Push piston and rod assemblies up and out through top of cylinder bores. Keep all components organized by cylinder number. Remove rod bearing inserts and keep with respective rods.
   ⚠Use rod bolt protectors or rubber hose over rod bolts to prevent cylinder bore damage during removal.
8. 8

   Remove old piston rings and clean pistons
   Using piston ring installer tool or ring expander, carefully remove all three rings from each piston (two compression rings and one oil control ring). Remove ring carefully to avoid damaging piston ring grooves. Clean ring grooves thoroughly using proper ring groove cleaner. Remove all carbon buildup from piston crown and skirts. Inspect pistons for cracks, scoring, or damage.
9. 9

   Inspect and prepare cylinder bores
   Use ridge reamer to remove any ridge at top of each cylinder bore. Measure each cylinder bore diameter at multiple points using bore gauge. Measure 1 inch below deck surface, at center, and near bottom in both thrust and perpendicular directions. Record all measurements. Maximum allowable taper is 0.002 inches, out-of-round 0.002 inches. Hone cylinders using proper technique with 280-320 grit stones to achieve 45-degree crosshatch pattern. Clean bores thoroughly with hot soapy water and dry completely. Apply light coat of assembly lube to prevent rust.
   ⚠If any cylinder is out of specification, engine block must be bored and oversized pistons installed. This procedure assumes bores are within specification.
10. 10

    Check piston ring end gaps
    Insert each new ring into its corresponding cylinder bore. Push ring down approximately 1 inch using inverted piston to ensure ring is square in bore. Measure ring end gap using feeler gauge. Compression ring gaps should be 0.010-0.020 inches, oil ring gaps 0.015-0.055 inches. If gap is too small, carefully file ring ends to achieve proper gap. If gap is too large, ring or bore is incorrect. Check all rings in all cylinders.
    ⚠Insufficient ring end gap will cause rings to butt together when heated, resulting in broken rings and engine damage.
11. 11

    Install piston rings
    Install oil control ring first (three-piece assembly): install expander, then lower side rail, then upper side rail. Ensure expander ends do not overlap. Install lower compression ring with identification mark facing up. Install top compression ring with identification mark facing up. Stagger ring end gaps 120 degrees apart. Verify rings rotate freely in grooves. Apply assembly lube to piston skirts and rings.
    ⚠Ring orientation is critical. Installing rings upside down will cause immediate failure and oil consumption.
12. 12

    Install pistons into cylinders
    Install rod bearings into connecting rods (ensure tang is properly seated in rod notch). Apply assembly lube to rod bearings. Install rod bolt protectors. Compress piston rings using proper ring compressor. With rings fully compressed, carefully tap piston into cylinder bore using wooden hammer handle. Ensure piston orientation mark faces front of engine. Guide connecting rod onto crankshaft journal. Remove rod bolt protectors. Install rod cap in correct orientation. Install NEW connecting rod bolts.
    ⚠Never force piston into bore. If resistance is felt, ring has escaped compressor and must be reset to prevent ring breakage.
    Torque spec

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

    Install crankshaft and main bearings
    Clean all main bearing saddles in block. Install upper main bearing inserts (ensure tang is seated in block notch). Apply assembly lube generously to all bearing surfaces. Carefully lower crankshaft into block. Install lower main bearing inserts into caps. Apply assembly lube to lower bearings. Install main bearing caps in correct positions and orientation. Install NEW main bearing cap bolts. Torque main bearing cap bolts in sequence: first all bolts to 75 Nm (55 lb-ft), then tighten additional 90 degrees. Verify crankshaft rotates freely by hand.
    ⚠Follow exact torque sequence from service manual. Improper sequence will cause bearing failure.
    Torque spec

    Main Bearing Cap Bolts75 Nm (55 lb-ft)
14. 14

    Torque connecting rod bolts
    Torque all connecting rod bolts to initial specification of 45 Nm (33 lb-ft). Then tighten each bolt an additional 90 degrees using torque angle gauge. After torquing, verify crankshaft still rotates freely. Check rod bearing clearances using Plastigage if reassembling with used bearings (clearance should be 0.0011-0.0018 inches).
    Torque spec

    Connecting Rod Bolts45 Nm (33 lb-ft)
15. 15

    Install oil pump pickup and oil pan
    Install new O-ring on oil pump pickup tube. Install pickup tube and torque bolt to specification. Clean oil pan and block mating surfaces thoroughly. Apply thin bead of RTV sealant to block where timing cover meets block. Install new oil pan gasket. Install oil pan and torque bolts in proper sequence to specification. Allow RTV to cure for minimum 30 minutes before adding oil.
    Torque spec

    Oil Pump Pickup Tube12 Nm (9 lb-ft)

    Oil Pan Bolts12 Nm (9 lb-ft)
16. 16

    Install cylinder heads
    Verify cylinder head and block surfaces are perfectly clean and flat. Install new head gaskets with orientation marks facing up and toward front of engine. Carefully lower cylinder heads onto block. Install NEW cylinder head bolts (lightly oil threads). Torque head bolts in proper sequence: first pass to 65 Nm (48 lb-ft), then tighten additional 90 degrees, then tighten additional 90 degrees again (total 180 degrees additional). Install camshafts in original positions with timing marks aligned.
    ⚠Cylinder head bolt sequence and torque angle are critical. Consult service manual for exact sequence diagram.
    Torque spec

    Cylinder Head Bolts65 Nm (48 lb-ft)
17. 17

    Reinstall timing components and accessories
    Install timing chains with marks properly aligned to camshaft and crankshaft gears. Install chain guides and tensioners. Install timing cover with new gasket and torque cover bolts. Reinstall all external accessories: water pump, power steering pump, A/C compressor, alternator. Install intake manifold with new gaskets. Install exhaust manifolds and turbochargers with new gaskets. Install valve covers with new gaskets. Reinstall all sensors and wiring.
    Torque spec

    Cover Bolts19 Nm (14 lb-ft)
18. 18

    Reinstall engine in vehicle
    Remove engine from stand and attach to engine hoist. Carefully lower engine into engine bay, aligning with transmission. Install transmission bellhousing bolts. Install engine mount bolts and torque to specification. Reconnect all electrical connections, fuel lines, coolant hoses, exhaust system, and accessories. Reinstall intercooler system, air intake, radiator, and front body components.
    Torque spec

    Mounting Bolts55 Nm (40 lb-ft)

Reassembly

1. Refill engine with 6 quarts Motorcraft 5W-20 synthetic blend oil and new oil filter
2. Refill cooling system with 13 quarts Motorcraft Orange coolant (50/50 mix)
3. Refill transfer case with 2.5 quarts Motorcraft Transfer Case Fluid
4. Refill front differential with 1.5 quarts 75W-90 GL-5 gear oil
5. Prime oil system by cranking engine with fuel pump fuse removed until oil pressure gauge shows pressure
6. Double-check all fluid levels, electrical connections, and hose clamps
7. Reconnect negative battery cable

Verification

• Start engine and verify oil pressure immediately rises to normal range (should show pressure within 2-3 seconds)
• Listen for any abnormal noises such as knocking, ticking, or rattling that would indicate assembly problems
• Allow engine to reach operating temperature and verify no coolant, oil, or fuel leaks from any connection points
• Verify both turbochargers are operating properly with no excessive shaft play or oil leaks
• Monitor oil consumption over first 500 miles - should not consume more than 1 quart
• Perform road test under various loads to verify proper engine performance and boost pressure
• Check for blow-by at oil filler cap - excessive blow-by indicates ring seating problems
• Recheck all fluid levels after first drive cycle and top off as necessary
• Change oil and filter after 500 mile break-in period to remove assembly lube and initial wear particles

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