Complete replacement of all engine block freeze plugs, requiring significant engine access and disassembly to reach all plug locations on the 2.5L A25A-FKS engine.

Warnings

Tools required

Parts

• Engine freeze plugs (complete set for A25A engine) × 1 — Use OEM specification
• Engine coolant × 1 — Toyota Super Long Life Coolant (Pink)
• Oil pan gasket × 1 — Use OEM specification
• Timing chain cover gasket × 1 — Use OEM specification
• Valve cover gasket × 1 — Use OEM specification
• Engine mount insulators (if damaged) × 1 — Use OEM specification
• Anaerobic sealant for freeze plugs × 1 — Use OEM specification

Fluids

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

Preparation

1. Ensure engine is completely cold (minimum 2 hours after last operation)
2. Disconnect negative battery terminal and wait 90 seconds for airbag system discharge
3. Remove engine cover and intake assembly
4. Drain engine coolant completely from radiator drain and engine block drain plugs into appropriate container
5. Drain engine oil and remove oil filter
6. Raise vehicle on lift or jack stands at all four corners with adequate working height
7. Remove front skid plate and undertray panels
8. Place reference marks on all electrical connectors with tape and labeling
9. Document routing of all vacuum lines, hoses, and wiring harnesses with photos

Procedure

1. 1

   Remove accessory drive components
   Remove serpentine belt by rotating tensioner counterclockwise. Remove alternator mounting bolts and secure alternator aside without disconnecting wiring. Remove A/C compressor mounting bolts and secure compressor aside without disconnecting refrigerant lines. Do not allow components to hang by wiring or hoses.
   Torque spec

   Mounting Bolts27 Nm (20 lb-ft)
2. 2

   Disconnect coolant and fuel system components
   Disconnect upper and lower radiator hoses at engine. Disconnect heater hoses at firewall connections. Disconnect coolant bypass hoses. Relieve fuel system pressure by removing fuel pump relay and cranking engine briefly. Disconnect fuel supply line at fuel rail using appropriate disconnect tool. Cap all open lines and ports.
   ⚠Fuel system may retain pressure even after relay removal. Have towels ready for fuel spillage.
3. 3

   Remove intake and exhaust manifolds
   Disconnect throttle body wiring and remove intake manifold assembly with throttle body attached. Remove all intake manifold mounting bolts working from outside to center. From underneath, disconnect exhaust manifold from exhaust pipe. Remove exhaust manifold heat shields and manifold mounting bolts. Remove exhaust manifold and gaskets.
   Torque spec

   Mounting Bolts27 Nm (20 lb-ft)
4. 4

   Remove valve cover and timing chain cover
   Disconnect ignition coil connectors and remove all four ignition coils. Remove PCV hoses from valve cover. Remove valve cover bolts in reverse of tightening sequence (outside to inside) and lift valve cover away. Set crankshaft to TDC on cylinder #1 by aligning timing marks. Remove crankshaft pulley bolt using holder tool. Remove timing chain cover bolts and carefully separate cover from block. Note dowel pin locations.
   ℹ️Timing chain cover contains integral water pump on this engine. Handle carefully to avoid damage.
   Torque spec

   Cover Bolts16 Nm (12 lb-ft)

   Gasket Bolts20 Nm (15 lb-ft)
5. 5

   Support engine and remove mounts
   Attach engine hoist with load leveler to factory lifting eyes on engine. Apply slight upward tension to support engine weight. Remove right side engine mount bolts at mount bracket and frame. Remove front engine mount through-bolt. Remove left side transaxle mount as necessary for access. Carefully raise engine approximately 4-6 inches to create working clearance. Use blocks to support engine in raised position if needed for extended work.
   ⚠️Ensure engine is balanced and secure on hoist before removing mounts. Use load leveler to prevent engine from shifting.
   Torque spec

   Mounting Bolts27 Nm (20 lb-ft)
6. 6

   Remove oil pan for bottom freeze plug access
   Remove all oil pan bolts working in crisscross pattern. Some bolts may be different lengths - note locations. Use plastic pry tool at designated pry points to separate oil pan from block. Do not damage sealing surfaces. Clean all gasket material from oil pan and block surfaces using gasket scraper. The A25A engine has 1-2 freeze plugs accessible from the bottom of the block with oil pan removed.
   Torque spec

   Gasket Bolts20 Nm (15 lb-ft)
7. 7

   Locate all freeze plug positions
   With engine raised and components removed, identify all freeze plug locations on the A25A engine. Typical locations: 2 plugs on rear of block (transmission side), 2-3 plugs on left side of block, 1-2 plugs on right side of block, and 1-2 plugs at bottom/oil pan area. Clean areas around all freeze plugs to verify their condition and prepare for removal. Total count should be 6-8 freeze plugs depending on engine casting.
   ℹ️Some freeze plugs may be hidden behind motor mount brackets or structural components requiring additional disassembly for access.
8. 8

   Remove old freeze plugs
   Using freeze plug removal tool or punch and hammer, strike one edge of freeze plug at an angle to rotate it within the bore. Once rotated, grip exposed edge with pliers and extract plug. Alternatively, drill small hole in center of plug, thread in slide hammer, and extract. Remove all old freeze plugs using consistent technique. Inspect bore surfaces for corrosion, pitting, or damage. Wire brush all freeze plug bores to clean metal and ensure proper sealing surface.
   ⚠Do not drive freeze plug completely into block. Rotate and extract to avoid damaging bore or pushing plug into water jacket.
9. 9

   Prepare and install new freeze plugs
   Verify new freeze plugs are correct size and fit properly in each bore - they should enter 1-2mm by hand pressure. Apply anaerobic sealant around outer edge of each freeze plug as specified. Position freeze plug square in bore with convex side facing out. Using freeze plug installation tool or appropriately sized socket and driver, drive plug straight into bore until seated flush or slightly below block surface (0-1mm depth). Plug should be perpendicular to bore throughout installation. Install all freeze plugs using same technique.
   ⚠Freeze plug must be driven in perfectly square. Cocked plugs will leak. Use installation tool with pilot that centers plug during driving.
   Torque spec

   Freeze Plug10 Nm (7 lb-ft)
10. 10

    Reinstall oil pan
    Apply new oil pan gasket or apply specified gasket maker in continuous bead pattern as per Toyota specifications. Position oil pan onto block and hand-start all bolts. Torque oil pan bolts in crisscross pattern from center outward to specification. Do not overtighten as this can distort pan and cause leaks. Allow gasket maker to cure per manufacturer instructions before adding oil.
    Torque spec

    Gasket Bolts20 Nm (15 lb-ft)
11. 11

    Reinstall timing chain cover
    Clean timing chain cover and block mating surfaces thoroughly. Install new gasket or apply gasket maker per Toyota specifications. Install dowel pins in block if removed. Position timing chain cover carefully onto block, ensuring all alignment features engage properly. Install all cover bolts and torque in specified sequence to specification. Reinstall crankshaft pulley with new bolt if required.
    Torque spec

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

    Reinstall valve cover and remaining components
    Install new valve cover gasket. Position valve cover onto cylinder head and install bolts in sequence from center outward. Torque bolts to specification. Reinstall ignition coils and connect electrical connectors. Reinstall PCV system hoses. Install exhaust manifold with new gaskets and torque bolts to specification. Install intake manifold with new gaskets and torque to specification working from center outward.
    Torque spec

    Gasket Bolts20 Nm (15 lb-ft)

    Mounting Bolts27 Nm (20 lb-ft)

    Sensor Bolts11 Nm (8 lb-ft)
13. 13

    Lower engine and reinstall mounts
    Using engine hoist, carefully lower engine back to normal position. Align engine mount brackets with frame mount points. Install and torque all engine mount bolts to specification. Start with front mount, then right side mount, then left side transaxle mount. Verify engine sits properly in mounts with no binding. Remove engine hoist.
    Torque spec

    Mounting Bolts27 Nm (20 lb-ft)
14. 14

    Reinstall accessory components
    Reinstall A/C compressor and torque mounting bolts to specification. Reinstall alternator and torque mounting bolts to specification. Reconnect all electrical connectors to alternator and compressor. Install serpentine belt per routing diagram. Verify belt tension is correct. Reconnect all coolant hoses and secure with new clamps. Reconnect fuel supply line.
    Torque spec

    Mounting Bolts27 Nm (20 lb-ft)
15. 15

    Fill fluids and pressure test cooling system
    Install new oil filter and fill engine with 5.0 quarts of Toyota Genuine 0W-20 engine oil. Close all coolant drains. Fill cooling system with Toyota Super Long Life Coolant (Pink) mixed to specification. Use coolant fill funnel to eliminate air pockets. With cooling system full, install cooling system pressure tester and pressurize to 16-18 psi. Inspect all freeze plug locations carefully for any signs of coolant seepage. Maintain pressure for 15 minutes minimum. Any leaks indicate improper installation requiring plug removal and reinstallation.
    ⚠Do not start engine if pressure test reveals any leaks. Freeze plug leaks will worsen dramatically under engine operation.

Reassembly

1. Ensure all coolant hoses are properly connected and secured with new clamps where applicable
2. Verify all electrical connectors are fully seated and locked, comparing to photos taken during disassembly
3. Double-check all torque specifications have been applied correctly, particularly freeze plugs and critical engine components
4. Confirm serpentine belt is properly routed and tensioned before starting engine
5. Reinstall all undertray panels and skid plates with proper fasteners

Verification

• With cooling system pressure tested successfully at 16-18 psi for 15 minutes with no leaks, remove pressure tester
• Reconnect negative battery terminal
• Start engine and allow to idle - monitor closely for any coolant leaks at freeze plug locations
• With engine at idle, check for oil leaks at oil pan gasket
• Allow engine to reach normal operating temperature while monitoring coolant level
• Check for proper heater operation indicating coolant circulation through entire system
• Perform final inspection of all freeze plug locations with engine at operating temperature - no seepage should be visible
• Rev engine to 2500 rpm several times and recheck all freeze plug locations for leaks
• After test drive, recheck coolant level when engine is cold and top off as necessary
• Inspect work area under vehicle after 24 hours and 100 miles for any signs of coolant or oil leakage

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