This procedure covers replacement of the internal water pump on the 3.5L EcoBoost V6 engine, which is driven by the timing chain and requires engine oil and coolant system service.

Warnings

Tools required

Parts

• Water pump assembly with gasket × 1 — Motorcraft PW-548 or equivalent
• Timing cover gasket × 1 — Use OEM specification
• Crankshaft front seal × 1 — Use OEM specification
• Engine oil filter × 1 — Motorcraft FL-910-S
• O-rings for coolant crossover × 1 — Use OEM specification
• RTV silicone sealant × 1 — Motorcraft TA-357 or equivalent

Fluids

• Motorcraft Orange Coolant — 13 qt
• Motorcraft 0W-20 Full Synthetic — 6 qt

Preparation

1. Ensure engine is completely cold to the touch
2. Disconnect negative battery cable and isolate from terminal
3. Remove engine cover and air intake assembly
4. Drain engine coolant completely into appropriate container
5. Drain engine oil and remove oil filter
6. Raise and support vehicle on jack stands if additional access is needed
7. Remove accessory drive belt and tensioner
8. Position drain pans under work area to catch residual fluids

Procedure

1. 1

   Support engine and remove right engine mount
   Install engine support bar across fender wells or attach engine hoist to secure lifting points. Support engine weight. Remove right side engine mount bolts and remove mount assembly to allow access to timing cover and crankshaft area.
2. 2

   Remove crankshaft pulley and harmonic balancer
   Remove crankshaft pulley center bolt using breaker bar (may require holding flywheel or using strap wrench). Use harmonic balancer puller to remove balancer from crankshaft. Do not strike balancer with hammer as this can damage crankshaft.
   ⚠Do not use a jaw-type puller that grips the outer edge of the balancer. Use only a puller that bolts to the balancer hub.
3. 3

   Remove timing cover bolts and accessories
   Disconnect any electrical connectors attached to timing cover area. Remove all timing cover bolts in sequence starting from outside and working inward. Note bolt lengths and positions as they vary. Carefully pry timing cover away from engine block. Clean all gasket surfaces thoroughly.
4. 4

   Mark and verify timing alignment
   Rotate crankshaft to TDC position on cylinder 1. Verify all timing marks on crankshaft and camshaft sprockets align with marks on engine block and cylinder heads. Use paint marker or scribe to mark chain position on sprockets. Photograph alignment for reference during reassembly.
   ⚠️Failure to properly mark and maintain timing chain alignment will result in severe engine damage upon startup.
5. 5

   Remove timing chain tensioners
   Remove timing chain tensioners by unbolting mounting bolts. The 3.5L EcoBoost has primary and secondary tensioners. Carefully release tensioner pressure according to service manual procedure. Keep tensioners organized for reinstallation.
6. 6

   Remove timing chain and guides
   Remove timing chain guide bolts. Slip timing chain off sprockets while maintaining reference marks. Remove chain guides as needed for access. Keep all components organized and labeled for correct reinstallation.
7. 7

   Remove water pump mounting bolts
   Locate water pump bolts on front of engine block behind timing chain area. Remove all water pump mounting bolts. Note that these bolts have a specific torque value of 10 Nm despite the 89 lb-ft reference being an error in some databases. Carefully remove water pump from engine block.
   ℹ️Coolant may drain from water pump cavity. Have drain pan positioned to catch residual coolant.
   Torque spec

   Water Pump Bolts25 Nm (18 lb-ft)
8. 8

   Clean and inspect mounting surfaces
   Thoroughly clean water pump mounting surface on engine block, removing all old gasket material and sealant. Inspect surface for corrosion, pitting, or damage. Clean timing cover mounting surfaces. Inspect timing chain, guides, and tensioners for wear and replace if necessary.
9. 9

   Install new water pump
   Install new water pump gasket or O-ring on pump. Apply thin bead of RTV sealant if specified by manufacturer. Position new water pump onto engine block ensuring proper alignment. Install water pump bolts and torque in crisscross pattern to specification.
   Torque spec

   Water Pump Bolts25 Nm (18 lb-ft)
10. 10

    Reinstall timing chain and components
    Install timing chain guides and torque bolts to specification. Reinstall timing chain onto sprockets ensuring all timing marks align exactly with reference marks made during disassembly. Install timing chain tensioners and activate according to service procedure. Verify all timing marks align correctly before proceeding.
    ⚠️Triple-check timing alignment before installing timing cover. Rotate crankshaft two full revolutions by hand and verify marks realign.
11. 11

    Install new timing cover and seal
    Install new crankshaft front seal into timing cover using seal driver. Install new timing cover gasket and apply RTV sealant at cylinder head-to-block joints. Position timing cover onto engine and install bolts finger tight. Torque timing cover bolts in proper sequence from center outward.
12. 12

    Reinstall harmonic balancer and crankshaft pulley
    Clean crankshaft snout and apply small amount of clean engine oil. Install harmonic balancer using installation tool, ensuring it seats fully. Install crankshaft pulley and torque center bolt to specification. Reinstall accessory drive belt tensioner and belt.
13. 13

    Reinstall engine mount and accessories
    Reinstall right engine mount and torque bolts to specification. Remove engine support equipment. Reconnect any electrical connectors. Install new engine oil filter and refill engine with specified amount of fresh 0W-20 synthetic oil.
14. 14

    Refill cooling system
    Refill cooling system with Motorcraft Orange Coolant to specification (13 quarts total capacity). Use vacuum fill tool if available to ensure complete fill and eliminate air pockets. If vacuum fill not available, fill slowly and burp system by running engine with heater on high while monitoring coolant level.

Reassembly

1. Reinstall air intake assembly and engine cover
2. Reconnect negative battery cable
3. Lower vehicle if raised
4. Double-check all fasteners are properly torqued
5. Verify no tools or parts are left in engine compartment

Verification

• Start engine and monitor for leaks at timing cover and water pump area
• Allow engine to reach operating temperature while monitoring coolant level
• Check for proper heater operation and verify no coolant leaks
• Monitor engine oil level and inspect for coolant contamination (milky appearance)
• Verify engine runs smoothly with no unusual noises from timing chain area
• Check coolant level again after cool-down and top off if necessary
• Perform test drive and recheck for leaks and proper engine operation
• Scan for diagnostic trouble codes and verify none are present

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