# SDR 2026FA0000279

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 20, 2026
- Submitted: April 20, 2026
- Operation: General aviation
- Aircraft: [N452X](https://openairdocs.org/aircraft/N452X), registered now
- Make and model: Mooney M20J
- Registry model: [Mooney M20J](https://openairdocs.org/model/mooney-m20j) (OpenAirDocs)
- Aircraft serial: 243357
- Aircraft time: 1,936 hours
- Engine: Lyc IO360A3B6
- Engine time: 2,589 hours
- Propeller: Mcauly B2D34C214
- System (JASC): [8530 · Reciprocating Engine Cylinder Section](https://openairdocs.org/jasc/8530)
- Part: Intake Valve
- Part number: AEL73988
- Condition: Broken
- Location: Engine
- Part time: 28 hours
- Component: Cylinder Assemb, Cont, IO360A3B6
- Component part number: TIST130CA
- Stage of operation: CR
- How discovered: O
- Nature of condition: R, J
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/2026FA0000279

## Discrepancy

PILOT REPORTED DURING CRUISE OPERATION A SUDDEN ENGINE ROUGHNESS WITH A LOSS OF POWER. EMERGENCY LANDING REQUESTED AND COMPLETED AT KOXR. INSPECTION OF ENGINE FOUND CYLINDER NUMBER 3 WITH HOLE THROUGH INTAKE PORT AND REAR BAFFLE. BORESCOPE INSPECTION REVEALED BROKEN INTAKE VALVE. INTAKE VALVE TOP AT RETAINER KEYS STILL CONTAINED IN SPRING CAP WITH VALVE ROTATOR INTACT. INTAKE VALVE HEAD CONTACTED PISTON AND LODGED IN INTAKE SEAT. COMPLETE BROKEN INTAKE VALVE STEM EXITED THE CYLINDER THROUGH THE INTAKE PORT AND REAR BAFFLE OVERBOARD DURING FLIGHT. NO OTHER ENGINE DAMAGE FOUND. ALL DAMAGE CONTAINED TO CYLINDER NUMBER 3.CONTINENTAL MOTORS (CMI) CONTACTED FOR WARRANTY AND INVESTIGATION OF FAILURE. CYLINDER RETURNED TO CMI FOR EVALUATION AND REPLACEMENT RMA10818. CMI NEW FAA-PMA CYLINDER KITS INSTALLED AT ENGINE OVERHAUL 28 HOURS AGO, CMI 8130-3 NUMBER 4516CA.

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