# SDR 99ZZZX3172

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 18, 1999
- Submitted: March 26, 2000
- Operation: General aviation
- Aircraft: [N12129](https://openairdocs.org/aircraft/N12129), registered now
- Make and model: Cessna 172M
- Registry model: [Cessna 172M](https://openairdocs.org/model/cessna-172m) (OpenAirDocs)
- Aircraft serial: 17261827
- Engine: Lyc O320E2D
- System (JASC): [8530 · Reciprocating Engine Cylinder Section](https://openairdocs.org/jasc/8530)
- Part: Valve
- Condition: Corroded
- Location: Nr 2 Cylinder
- Part time: 5,174 hours
- Stage of operation: IN
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/99ZZZX3172

## Discrepancy

DURING A ROUTINE COMPRESSION CHECK, CYLINDER AIR PRESSURE ABOVE 6 PSI COULD NOT BE MAINTAINED IN NR 2 CYLINDER.  AIR WAS FELT ESCAPING FROM THE INDUCTION AIRBOX.  MECHANIC TAPPED ON INTAKE VALVE WITH A DRIFT.  SUBSEQUENT COMPRESSION CHECKS FAILED AS WELL.  CYLINDER REMOVED.  FOUND EXHAUST VALVE CORRODED AND PITTED BEYOND LIMITS.  INTAKE AND EXHAUST VALVES WERE RE-SEATED AND CYLINDER BENCH CHECKED.

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