Narrative:

I was flying in a ce-172SP G1000. At the time of the emergency I was cruising at 6;000 ft MSL and flying about 105 knots indicated. About 30 NM from ZZZ I had a sudden loss of power and a violent shaking of the engine and airframe. Noticing the loss in power I immediately checked the fuel switch and applied mixture full rich and added power and switched to the engine system menu on the G1000 to see what exactly was happening. Under the display for cht and egt for each cylinder; cylinder number 3 was showing zero for both. Realizing I could have a major problem with the engine I decided to [advise ATC] and ask for vectors to the nearest airport to land as soon as possible. ATC help was immediate and had me fly a heading of 090 and proceed directly to ZZZ1 which was 5 NM away. As I was flying toward the airport I told the controller I had 2 souls; 30 gallons of fuel and that I could have a failed third cylinder. About half way to ZZZ1 I started to get a little more power back but it still was lacking significantly. After the mechanics checked the aircraft 3 days later; they saw that cylinder number 3 had zero compression and was ruined. I don't know what caused the problem; and am not really sure either. As far as preventing recurrence goes; besides making sure that aircraft like these that are flown this much receive more than required maintenance checks; nothing else comes to mind. Nothing should have been done differently; I performed the emergency procedure to the best of my ability.

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Original NASA ASRS Text

Title: C172 pilot reported an engine problem that resulted in a diversion to the nearest airport.

Narrative: I was flying in a CE-172SP G1000. At the time of the emergency I was cruising at 6;000 ft MSL and flying about 105 knots indicated. About 30 NM from ZZZ I had a sudden loss of power and a violent shaking of the engine and airframe. Noticing the loss in power I immediately checked the fuel switch and applied mixture full rich and added power and switched to the engine system menu on the G1000 to see what exactly was happening. Under the display for CHT and EGT for each cylinder; Cylinder Number 3 was showing zero for both. Realizing I could have a major problem with the engine I decided to [advise ATC] and ask for vectors to the nearest airport to land as soon as possible. ATC help was immediate and had me fly a heading of 090 and proceed directly to ZZZ1 which was 5 NM away. As I was flying toward the airport I told the controller I had 2 souls; 30 gallons of fuel and that I could have a failed third cylinder. About half way to ZZZ1 I started to get a little more power back but it still was lacking significantly. After the mechanics checked the aircraft 3 days later; they saw that cylinder Number 3 had zero compression and was ruined. I don't know what caused the problem; and am not really sure either. As far as preventing recurrence goes; besides making sure that aircraft like these that are flown this much receive more than required maintenance checks; nothing else comes to mind. Nothing should have been done differently; I performed the emergency procedure to the best of my ability.

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.