Cylinder Head Resurface

This procedure covers removing, inspecting, machining, and reinstalling the cylinder head on a 2016-2021 Honda Civic 1.5L turbo engine to correct warpage or surface defects.

Warnings

Tools required

Parts

• Cylinder head gasket × 1 — 12251-5AA-A01
• Cylinder head bolt set (TTY) × 1 — Use Honda OEM TTY bolt kit
• Intake manifold gasket × 1 — 17105-5AA-A01
• Exhaust manifold gasket × 1 — 18115-5AA-A01
• Valve cover gasket × 1 — 12030-5AA-A01
• Spark plug tube seals × 4 — Use OEM specification
• Timing chain tensioner gasket × 1 — Use OEM specification
• VTC actuator gasket × 1 — Use OEM specification
• Thermostat housing gasket × 1 — Use OEM specification
• Anti-seize compound × 1 — High-temperature rated
• Engine coolant × 1 — Honda Type 2 Blue
• Engine oil and filter × 1 — 0W-20

Fluids

• Honda Type 2 Coolant (Blue) — 6 qt
• Honda Genuine 0W-20 — 4 qt

Preparation

1. Ensure engine is completely cold before starting work
2. Disconnect negative battery terminal and wait 3 minutes for SRS system discharge
3. Relieve fuel system pressure by removing fuel pump fuse and cranking engine until it stalls
4. Drain engine coolant completely into appropriate container
5. Drain engine oil and remove oil filter
6. Remove engine cover and air intake assembly
7. Label all electrical connectors, vacuum lines, and hoses with tape for reinstallation reference
8. Take photos of routing for fuel lines, coolant hoses, and wiring harness

Procedure

1. 1

   Remove Turbocharger and Exhaust Components
   Disconnect oxygen sensor connectors. Remove turbocharger heat shields. Disconnect turbocharger oil feed and drain lines (have shop towels ready for oil spillage). Remove turbocharger support bracket. Unbolt turbocharger from exhaust manifold and remove as assembly. Remove exhaust manifold from cylinder head, working from center bolts outward.
   ⚠Support turbocharger weight during removal to prevent damage to oil lines or mounting studs
2. 2

   Remove Intake Manifold and Fuel System Components
   Disconnect throttle body connector and coolant bypass hoses. Remove PCV hose and brake booster vacuum line. Disconnect fuel injector connectors and fuel rail. Remove fuel rail with injectors attached (do not separate unless necessary). Remove intake manifold bolts in reverse of tightening sequence and lift manifold away. Cap all open ports.
   ⚠Fuel rail is under residual pressure even after system relief. Have towels ready for fuel spillage
3. 3

   Remove Valve Cover and Accessory Components
   Disconnect ignition coil connectors and remove all four coils. Remove PCV valve. Unbolt valve cover in reverse sequence (outside to inside pattern). Carefully lift valve cover away, breaking seal with plastic scraper if needed. Remove any remaining brackets, sensors, or coolant passages attached to cylinder head.
4. 4

   Set Engine to TDC and Lock Timing
   Rotate crankshaft clockwise using 19mm socket on crankshaft bolt until cylinder #1 is at TDC compression stroke. Verify TDC mark on crankshaft pulley aligns with timing cover pointer. Install timing pin through VTC actuator to lock camshaft position. Verify timing chain colored links align with camshaft and crankshaft timing marks.
   ⚠️Do NOT rotate crankshaft counterclockwise or after timing chain is loosened. This will cause valve-to-piston contact
5. 5

   Remove Timing Chain Components
   Remove timing chain auto-tensioner by loosening mounting bolts while supporting tensioner. Remove VTC actuator bolt (requires holding camshaft with wrench on camshaft hex). Remove VTC actuator and timing chain together. Remove camshaft sprocket if required. Support timing chain with wire to prevent it from falling into timing cover.
   ⚠Keep timing chain supported and do not allow it to fall into lower timing cover area
6. 6

   Remove Camshaft and Rocker Assembly
   Loosen camshaft bearing cap bolts in reverse sequence (from outer caps to center), loosening each bolt 1/4 turn at a time to release valve spring tension evenly. Remove bearing caps and label them for position. Lift camshaft straight up and away. Remove rocker arm assembly if head will be sent to machine shop, or leave in place if only lapping valves.
   ⚠Camshaft bearing caps are not interchangeable. Keep them in order and orientation
7. 7

   Remove Cylinder Head
   Remove cylinder head bolts in reverse of tightening sequence (outside bolts first, working toward center). Loosen each bolt gradually in multiple passes. Once all bolts are removed, carefully break head gasket seal using plastic pry points (never metal tools on sealing surfaces). Lift cylinder head straight up to avoid damaging alignment dowels. Place head on wood blocks with combustion chambers facing up.
   ℹ️Head is heavy (approximately 40 lbs). Use assistant or proper lifting technique
8. 8

   Inspect and Clean Cylinder Head
   Remove all carbon deposits from combustion chambers using appropriate solvent and soft brushes. Clean all gasket surfaces with plastic scraper only (never use metal scrapers or abrasive pads on aluminum surfaces). Inspect for cracks in combustion chambers, valve seats, and between valve seats. Check valve guides for wear. Clean all oil and coolant passages with solvent and compressed air.
9. 9

   Measure Cylinder Head Warpage
   Using calibrated straight edge and feeler gauge, check head deck surface for warpage lengthwise, crosswise, and diagonally. Measure at minimum 6 locations. Maximum allowable warpage is 0.002 inches (0.05mm). If warpage exceeds 0.002 inches, resurfacing is required. Record all measurements before machining.
   ⚠Honda specifies maximum material removal of 0.008 inches (0.2mm) total from cylinder head deck. Check service history for previous resurfacing
10. 10

    Resurface Cylinder Head
    Have cylinder head resurfaced by qualified machine shop to remove minimum material necessary to achieve flat surface within 0.001 inch (0.025mm). Typical resurfacing removes 0.003-0.006 inches. After machining, verify final deck height and ensure combined head and block removal does not exceed Honda specifications. Valve seat reconditioning may be required after resurfacing.
    ℹ️Head gasket thickness may need adjustment if significant material is removed. Consult Honda specifications
11. 11

    Prepare Block Surface and Install New Head Gasket
    Clean engine block deck surface thoroughly with plastic scraper and solvent. Remove all old gasket material and carbon. Verify block surface flatness using straight edge. Clean cylinder bores of any debris. Ensure alignment dowels are in place. Place new cylinder head gasket on block with UP mark facing upward. Do NOT use any sealant on multi-layer steel head gasket.
    ⚠Head gasket is directional. Verify UP marking is visible and oriented correctly before installing head
12. 12

    Install Cylinder Head with New TTY Bolts
    Carefully lower cylinder head onto block, aligning with dowel pins. Install NEW cylinder head bolts finger-tight in sequence. Using torque wrench, tighten all bolts in sequence to 29 Nm (21 lb-ft), then to 65 Nm (48 lb-ft). Finally, using angle gauge, rotate each bolt an additional 90 degrees in sequence, then another 90 degrees (180 degrees total angle tightening). Verify each bolt receives angle tightening.
    ⚠️NEVER reuse old cylinder head bolts. TTY bolts stretch during installation and cannot be reused
    Torque spec

    Cylinder Head Bolts65 Nm (48 lb-ft)
13. 13

    Install Camshaft and Rocker Assembly
    Apply clean engine oil to camshaft journals and lobes. Install rocker arm assembly if removed. Position camshaft with timing mark facing up. Install bearing caps in original positions with directional arrows pointing toward timing chain side. Tighten bearing cap bolts in sequence from center outward, in multiple passes, to specified torque. Verify camshaft rotates freely.
14. 14

    Reinstall Timing Chain and VTC Actuator
    Rotate crankshaft to TDC position if moved. Install timing chain over crankshaft sprocket with colored link aligned with crankshaft timing mark. Route chain over camshaft sprocket/VTC actuator, aligning colored link with camshaft timing mark. Install VTC actuator onto camshaft, ensuring timing pin can be inserted. Tighten VTC bolt to specification. Install timing chain tensioner with new gasket and tighten bolts to specification.
    ⚠️Verify timing marks alignment three times before proceeding. Incorrect timing causes immediate engine damage
    Torque spec

    Gasket Bolts19 Nm (14 lb-ft)
15. 15

    Install Valve Cover and Remaining Components
    Install new valve cover gasket and spark plug tube seals. Clean valve cover mating surface. Position valve cover and install bolts finger-tight. Tighten valve cover bolts in sequence from center outward to 10 Nm (7 lb-ft). Install ignition coils and connect electrical connectors. Install intake manifold with new gasket, tightening bolts to 25 Nm (18 lb-ft) in sequence. Install exhaust manifold with new gasket using anti-seize on studs, tightening nuts to 30 Nm (22 lb-ft) from center outward. Reinstall turbocharger assembly, fuel rail, and all sensors and hoses per photos and labels.
    Torque spec

    Cover Bolts15 Nm (11 lb-ft)

    Intake Manifold Bolts25 Nm (18 lb-ft)

    Exhaust Manifold Nuts30 Nm (22 lb-ft)

Reassembly

1. Double-check all electrical connectors are reattached and secure
2. Verify all coolant hoses and clamps are properly installed
3. Ensure turbocharger oil feed and drain lines are torqued to specification without cross-threading
4. Install new engine oil filter and refill with 4 quarts Honda Genuine 0W-20 oil
5. Refill cooling system with Honda Type 2 Blue coolant and bleed air per Honda procedure
6. Reconnect battery negative terminal

Verification

• Remove timing pin from VTC actuator before attempting to start
• Manually rotate crankshaft two complete revolutions clockwise by hand to verify no interference and proper valve operation
• Check for proper compression using compression tester on all cylinders (should be 185-220 psi with less than 15% variance)
• Start engine and verify no unusual noises, monitoring for oil pressure within 10 seconds
• Allow engine to reach operating temperature and verify no coolant or oil leaks at head gasket, valve cover, or manifold areas
• Check for exhaust leaks at manifold and turbocharger connections
• Verify smooth idle and proper engine response to throttle input
• Test drive vehicle to verify proper boost pressure and no abnormal performance issues
• Recheck cylinder head bolt torque after first heat cycle (optional per Honda service guidelines)

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

Chasing one of these codes and not sure which part is guilty? Ask a master mechanic about YOUR car →

More procedures for this vehicle