# SDR 98ZZZX1448

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: March 18, 1998
- Submitted: March 26, 2000
- Operation: General aviation
- Aircraft: [N54048](https://openairdocs.org/aircraft/N54048), registered now
- Make and model: Cessna 172P
- Registry model: [Cessna 172P](https://openairdocs.org/model/cessna-172p) (OpenAirDocs)
- Aircraft serial: 17274857
- Engine: Lyc O320D2J
- System (JASC): [8530 · Reciprocating Engine Cylinder Section](https://openairdocs.org/jasc/8530)
- Part: Valve Seat
- Condition: Damaged
- Location: Nr 3 Cyl Exh Vlv
- Part time: 4,627 hours
- Stage of operation: IN
- Nature of condition: E, R
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/98ZZZX1448

## Discrepancy

DURING AIRCRAFT RUN-UP, THE PILOT NOTICED THE ENGINE WAS RUNNING ROUGH.  THE MECHANIC PULLED A COMPRESSION CHECK AND FOUND THAT NR 3 CYLINDER HAD NO COMPRESSION.  FURTHER INVESTIGATING AND CYLINDER REMOVAL SHOWED THE EXHAUST VALVE SEAT INSIDE THE CYLINDER HAD SLIPPED OUT FROM ITS GROOVE; THUS, NOT ALLOWING FOR PROPER VALVE SEATING.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.