# SDR 2025FA0000400

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: June 11, 2025
- Submitted: June 11, 2025
- Operation: General aviation
- Aircraft: [N187CA](https://openairdocs.org/aircraft/N187CA), registered now
- Make and model: Cessna 172S
- Registry model: [Cessna 172S](https://openairdocs.org/model/cessna-172s) (OpenAirDocs)
- Aircraft serial: 172S13102
- Aircraft time: 326 hours
- Engine: Lyc IO360L2A
- Engine time: 326 hours
- Propeller: Mcauly 1A170E
- System (JASC): [8530 · Reciprocating Engine Cylinder Section](https://openairdocs.org/jasc/8530)
- Part: Valve Guide
- Part number: 16R22126
- Condition: Coked
- Location: Engine
- Part time: 326 hours
- Stage of operation: CR
- How discovered: O
- Nature of condition: R, J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/2025FA0000400

## Discrepancy

CREW REPORTED ROUGH RUNNING ENGINE/VIBRATION IN CRUISE FLIGHT LASTING 2-3 MINUTES ALONG WITH A # 2 CYLINDER EGT FLUCTUATION. TROUBLESHOT PROBLEM TO FIND # 2 CYLINDER EXHAUST VALVE STICKING.

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