# SDR 99ZZZX338

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 21, 1998
- Submitted: March 26, 2000
- Operation: General aviation
- Aircraft: [N954CC](https://openairdocs.org/aircraft/N954CC), registered now
- Make and model: Cessna 182Q
- Registry model: [Cessna 182Q](https://openairdocs.org/model/cessna-182q) (OpenAirDocs)
- Aircraft serial: 18265290
- Engine: Cont O470U
- System (JASC): [8530 · Reciprocating Engine Cylinder Section](https://openairdocs.org/jasc/8530)
- Part: Valve Guide
- Part number: 643767
- Condition: Worn
- Location: Nr 4 Cylinder
- Part time: 478 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/99ZZZX338

## Discrepancy

DURING A ROUTINE 100-HOUR INSPECTION, THE NR 4 CYLINDER WAS FOUND TO HAVE LEAKAGE PAST THE EXHAUST VALVE.  FURTHER INVESTIGATION REVEALED A WORN OUT EXHAUST VALVE GUIDE.  REPLACING THE GUIDE AND RE-FACING THE EXHAUST VALVE RESOLVED THE PROBLEM.  SUBMITTER SUGGESTED POSSIBLE CAUSE AS DEFECTIVE PARTS OR ASSEMBLY PROCESS FROM THE FACTORY.

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