Skyhawk 172/Cutlass 172
Flight Crew Instrument; Flight Crew Private
Aircraft Equipment Problem Less Severe
Air Traffic Control Issued New Clearance; Flight Crew Diverted; Flight Crew Landed As Precaution
Aircraft
We were cleared for takeoff [and] were assigned to fly 3000 feet heading 150. Just before reaching 3000 feet; we got cleared to climb to 5000 feet heading 240. Just before reaching 5000 feet we heard a loud pop from the engine followed by an RPM drop of about 500 RPM. It took a moment for the engine to regain its normal RPM (perhaps 2 seconds). My crew partner and I talked to each other to see if either of us knew what just had happened. As we concluded that we didn't know the reason for the pop and RPM drop; we requested to divert back to [a nearby airport] to be cautious. Departure asked if we would like emergency [handling]. We responded saying that our engine is running fine now and verified by referencing all engine instruments. Departure directed us to [the nearby airport] and declared [on] our behalf an emergency to give us priority. To conclude; we decided it was safer to turn around and fly back to have our plane examined. As we landed a fire fighter truck and the police was waiting for us and making sure that we arrived safely.
C172 pilot reported diverting to an alternate airport after hearing a 'pop' and noticing an RPM drop.