2016-2017 Honda Civic Cylinder Head Gasket Warranty Extension

Honda has announced a warranty extension for the cylinder head gasket on certain 2016-2017 Civic 1.5T (CVT) vehicles. This extension, detailed in Service Bulletin 26-099, addresses potential issues where the cylinder head gasket's effectiveness may be reduced.

Bulletin Details and Revision History

Service Bulletin 26-099, Version 3, was issued on September 25, 2026. This version supersedes version 2 and includes several revisions. Changes were made to the BACKGROUND and WARRANTY INFORMATION sections, with new statements and notes added. The REQUIRED MATERIALS and TOOL INFORMATION sections were updated. Additionally, the process for mating surface cleaning and inspecting the engine block for warpage was moved to Job Aid AJA31119, titled "Inspecting Cylinder Head and Engine Block for Warpage."

Symptoms

Owners of affected 2016-2017 Honda Civic models may experience several symptoms related to the cylinder head gasket issue. These can include engine overheating, noticeable coolant loss, and engine misfires. These symptoms indicate a potential problem with the Honda Civic cylinder head gasket.

Fault Codes / DTCs

In conjunction with the physical symptoms, the vehicle's onboard diagnostic system may store specific diagnostic trouble codes (DTCs). Service Bulletin 26-099 notes that DTCs P0300 through P0304 may be stored. These codes indicate a misfire condition in one or more cylinders:

• P0300: Random/Multiple Cylinder Misfire Detected
• P0301: Cylinder 1 Misfire Detected
• P0302: Cylinder 2 Misfire Detected
• P0303: Cylinder 3 Misfire Detected
• P0304: Cylinder 4 Misfire Detected

It is important to note that the presence of these DTCs is not strictly required for a repair under this warranty extension. The bulletin explicitly states, "An ALL DTC check result with or without DTCs P0300 through P0304 are acceptable" for warranty claims.

Diagnosis / Trigger Conditions

To diagnose the issue, technicians will perform a comprehensive inspection for coolant leaks. The process begins with the engine cold, followed by an "ALL DTC Check" using the i-HDS diagnostic system to document any stored PGM-FI DTCs. A cooling system pressure tester (SVTS272A) is then installed after topping off coolant if necessary.

The engine is run until it reaches normal operating temperature (194°F or 90°C), indicated by the cooling fan cycling on. The cooling system pressure is checked, and if it's below 18 psi, the pressure is brought up to 18 psi using the tester. The bulletin clarifies that "The cooling system pressure could be higher than 18 psi when vehicle reaches normal operating temperature, which is acceptable."

Next, all four spark plugs are removed. A borescope, such as the Snap-on 5.5 mm Borescope (BK5600Dual55 or equivalent), is used to inspect all cylinders for coolant entering at the head gasket. The inspection requires a 90° camera to capture a side view, focusing on the area where the cylinder head meets the block, and scanning 360 degrees around the cylinder. If coolant is observed, a picture must be taken of the borescope screen showing the leak, the VIN, repair order number, date, and engine number. This image must clearly show the coolant on the cylinder wall and the engine number for warranty claim submission. "Claims submitted without this image will be denied." The image must be saved in PDF format.

If coolant is indeed leaking into the cylinders, the technician proceeds to determining necessary repairs. If no coolant leak is found, the bulletin states, "This bulletin does not apply. Continue with normal troubleshooting."

Important Warnings and What Owners Should Know

Honda is extending the warranty coverage for the Honda Civic cylinder head gasket condition until May 31, 2027, regardless of the vehicle's time in service or mileage. Any repair orders issued after this date will not be valid.

Crucially, this warranty extension applies to any vehicle, even if it has been declared a total loss, sold for salvage by a financial institution or insurer, or has a branded or similar title under any state's law. Owners of affected vehicles will receive a notification of this campaign.

For repairs involving the replacement of the cylinder head or engine short block, prior approval from the Repair Validation Team is required, as outlined in Job Aid AJA31119. Warranty claims for these major replacements will be denied without this approval. However, the bulletin explicitly states, "Do not call for approval if the cylinder head and engine block are within specifications."

Technicians are also warned about specific procedures: "Do not use power tools which can damage the cylinder head and block." Also, when performing a short block replacement, "If the wrong short block is ordered the alternator may not fit." During A/C compressor removal, technicians are instructed, "Do not disconnect the A/C hoses."

Repair Procedure Summary

The repair procedure for the Honda Civic cylinder head gasket issue varies depending on the extent of the damage, determined by whether the cylinder head or engine block is warped. The bulletin outlines four main repair scenarios, each with a specific operation number, flat rate time, defect code (6A700), symptom code (QPQ00), and template ID:

• Repair Procedure #1 - Head Gasket Only (Operation Number 1105E6): This procedure is performed if neither the cylinder head nor the engine block is warped. The repair involves replacing only the cylinder head gasket (part number 12251-5BA-A01). The flat rate time for this operation is 11.5 hours. The associated template ID is A26099A.

  • Process: Install a new cylinder head gasket and dowel pins. Visually inspect cylinder head bolts for damage; replace if necessary. Apply new engine oil to bolt threads. Torque cylinder head bolts in sequence to 30 N-m (22 lb-ft), then perform an angle torque of an additional 165° for new bolts or 140° for reused bolts. Complete the cylinder head installation steps, drain and refill engine oil, perform a PCM Reset, CKP Pattern Clear/Learn Procedure, and PCM Idle Learn Procedure.

• Repair Procedure #2 - Cylinder Head Replacement (Operation Number 1105E7): This procedure is performed if the cylinder head is warped but the engine block is not. The repair involves replacing the cylinder head (part number 10003-5AA-A00) along with the head gasket. The flat rate time is 11.9 hours. The associated template ID is A26099B.

  • Process: Swap parts from the old cylinder head to the new one, including the VTC Oil Control Solenoid Valve B (torque to 12 N-m / 9 lb-ft with a new O-ring) and the fuel rail and injectors (using new clips, O-rings, and back-up rings). After these components are transferred, proceed with the steps outlined in Repair Procedure #1 for installing the cylinder head and completing the repair.

• Repair Procedure #3 - Short Block Replacement (Operation Number 1105E8): This procedure is performed if the engine block is warped. The repair involves replacing the engine short block (part number 10002-5AA-A01 for 2016 all and 2017 thru engine S/N 2072066; 10002-5AA-A04 for 2017 from engine S/N 2072067) and the head gasket. The flat rate time is 14.7 hours. The associated template ID is A26099C.

  • Process: This is an extensive procedure that includes removing the alternator, water pump, front grille cover, A/C compressor (without disconnecting hoses), turbocharger support bracket, knock sensor, starter, and engine wiring harness. The engine is then lifted, transmission fluid drained, and components like the lower torque rod, exhaust pipe, torque converter, intermediate shaft, and driveshaft are removed. Parts such as the Drive Plate (torque to 74 N-m / 55 lb-ft), Knock Sensor (torque to 22 N-m / 16 lb-ft), CKP Sensor (torque to 12 N-m / 9 lb-ft with new seal), Cam Chain Drive Sprocket, and Cam Chain tensioner sub arm are transferred to the new short block. After installing the new short block, the vehicle proceeds to either Repair Procedure #1 (if the cylinder head is not replaced) or Repair Procedure #2 (if the cylinder head is also replaced).

• Repair Procedures #3, then #2 - Head Gasket, Cylinder Head, and Short Block Replacement (Operation Number 1105E9): If both the cylinder head and engine block are warped, this combined approach is used. The flat rate time is 14.8 hours. The associated template ID is A26099D.

  • Process: First, the steps for Short Block Replacement (Repair Procedure #3) are completed. Then, the steps for Cylinder Head Replacement (Repair Procedure #2) are performed to install the new cylinder head and complete the repair.

All repair procedures require a PCM Reset, CKP Pattern Clear/Learn Procedure, and PCM Idle Learn Procedure. An alignment is only required if the short block has been replaced.

Required Tools or Parts

Technicians will utilize a range of specialized tools and parts for these repairs. Key tools include:

• Cooling System Pressure Tester (SVTS272A)
• Snap-on 5.5 mm Borescope (BK5600Dual55 or equivalent)
• Engine Support Hanger Tool (AART1256)
• Universal Lift Eyelet (07AAK-SNAA600)
• Support Eyelet (07AAK-SNAA120)
• Spacer 4X.375 (07AAB-59BA110)
• Bolt M10x1.25-30MM (10.9)
• Bolt M10x1.25-20MM (10.9)
• Bolt M8x1.25-30MM (10.9)
• Bolt M8x1.25-20MM (10.9)
• Straight Edge 18" (07AAJ-59BA110)
• Feeler Gauge (07AAJ-59BA120)
• Torque Angle Gauge (TA360 or Commercially Available)

Specific part numbers for components that may be replaced include:

• GASKET, CYLINDER HEAD (NIPPON LEAKLESS): 12251-59B-A01
• GASKET, HEAD COVER (HEAD COVER GASKET): 12341-59B-013
• FILTER, OIL: 15400-RTA-003
• FILTER ASSY., TURBOCHARGER OILFEED: 15533-598-003
• OIL SEAL, CONTROL VALVE: 15832-RAA-A01
• PIPE SET, FUEL JOINT (MSDS): 16012-59B-315
• GASKET, IN. MANIFOLD: 17105-5AA-004
• GASKET, TURBOCHARGER JOINT IN.: 17285-5AA-A01
• GASKET, TURBOCHARGER JOINT OUTLET: 17286-5AA-A01
• GASKET A, TURBOCHARGER: 18233-59B-004
• GASKET B, TURBOCHARGER: 18234-59B-004
• GASKET, EX. PIPE: 18302-SP0-003
• GASKET, DRAIN (DENSO): 19012-671-300
• GASKET, THERMOSTAT CASE: 19321-59B-004
• GASKET, TURBOCHARGER PIPE: 19524-59B-004
• NUT, SELF-LOCK (10MM) (CATALYST): 90012-598-004
• BOLT, FLANGE (12X40) (SIDE MOUNT BOLT): 90162-T0A-A00
• BOLT, FLANGE (14X64) (SIDE MOUNT): 90166-TBA-A00
• NUT, SELF-LOCK (10MM) (EXHAUST): 90212-SA5-003
• NUT, FLANGE (14MM) (SIDE MOUNT): 90371-SJD-003
• OIL SEAL (43X58X7) (CRANK SEAL): 91212-59B-003
• HPFP O-RING: 91311-5R1-J01
• O-RING (31.2X4.1) (NOK) (CONNECTING PIPE): 91314-PH7-003
• WASHER, DRAIN PLUG: 94109-14000
• THERMOSTAT SET: 06193-59B-306
• GENERAL ASSY., CYLINDER HEAD: 10003-5AA-A00
• CLIP, INJECTOR: 16451-5R1-J01
• SEAL SET, INJECTOR: 16453-521-J00
• GENERAL ASSY., CYLINDER BLOCK: 10002-5AA-A01 (for 2016 all and 2017 thru engine S/N 2072066) or 10002-5AA-A04 (for 2017 from engine S/N 2072067)
• GASKET, EX, PIPE: 18303-T2B-A01
• O-RING, WATER PASSAGE (OIL): 19411-5AA-A01
• NUT, FLANGE (10MM) (SWAY BAR LINK): 90002-S10-000
• BOLT, GEAR BOX MOUNTING: 90108-TL1-G00
• BOLT, FLANGE (14X100) (TORQUE MOUNT): 90161-T5A-000
• BOLT, FLANGE (14X33) (TORQUE ROD): 90164-T6E-000
• BOLT, FLANGE (10X30) (SIDE MOUNT): 90171-TBA-A00
• NUT, SELF-LOCK (10MM) (EXHAUST): 90212-SA5-003
• NUT, SELF-LOCK (12MM) (KNUCKLE): 90215-SB0-003
• NUT, SPINDLE (24MM): 90305-SD4-003
• GASKET (10MM): 90471-59C-000
• WASHER, DRAIN PLUG (18MM): 90471-PX4-000
• WASHER, SEALING (28MM): 90401-PR4-000

Required materials include Hondabond HT (08718-0004), various Brake Cleaners (08700-9200, 08700-9222, 08700-SBPCA), Long Life Antifreeze/Coolant Type 2 (08CLA-P99-0F0A8), CVT Fluid HCF2 (08200-HCF2), and Honda 0W-20 Motor Oil (08798-9163).

Owner Action

Owners of eligible 2016-2017 Honda Civic 1.5T (CVT) vehicles will be notified by Honda regarding this warranty extension. If you experience symptoms such as overheating, coolant loss, or misfires, or if your vehicle stores DTCs P0300 through P0304, you should contact an authorized Honda automobile dealer to check your vehicle's eligibility and schedule an inspection and repair. Ensure to inquire about the iN VIN status for eligibility. Remember that this warranty extension for the Honda Civic cylinder head gasket is valid until May 31, 2027.

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Source: NHTSA ID: 11037711