Narrative:

Enroute instructor noticed that the engine was running abnormally loud and checked engine power level. Power level read 20% and 1400 rpms with 11 gph fuel burn and 123 KIAS. Noting abnormal indications; instructor pilot (ip) told student to fly direct [to home field]. During the flight back; power was set to minimum cruise 100 knots to reduce any engine strain and monitored all instruments; everything was normal aside from power % and tach. Aircraft was told to expect the arrival. Instructor requested straight in as a better option but was told unable (approach was unaware of the issue at this time); about 20 seconds after this statement; instructor and pilot both felt an unusual knock; that was enough for instructor to call for a diversion to the nearest airport. Pilot told approach that we were not stating an emergency but we were receiving unusual engine indications and was diverting with 2 souls and 3 1/2 hours of fuel.

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Original NASA ASRS Text

Title: SR20 instructor with student reported a low power reading in cruise and elected to divert to the nearest suitable airport.

Narrative: Enroute instructor noticed that the engine was running abnormally loud and checked engine power level. Power level read 20% and 1400 RPMs with 11 GPH fuel burn and 123 KIAS. Noting abnormal indications; Instructor Pilot (IP) told student to fly direct [to home field]. During the flight back; power was set to minimum cruise 100 Knots to reduce any engine strain and monitored all instruments; everything was normal aside from Power % and Tach. Aircraft was told to expect the arrival. Instructor requested straight in as a better option but was told unable (Approach was unaware of the issue at this time); about 20 seconds after this statement; instructor and pilot both felt an unusual knock; that was enough for instructor to call for a diversion to the nearest airport. Pilot told Approach that we were not stating an emergency but we were receiving unusual engine indications and was diverting with 2 souls and 3 1/2 hours of fuel.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.