Van's Aircraft RV-12 Maintenance Manual page 174

Symptom
Vibration at idle
Vibration at specific
RPM
Excessive rattling
Corrosion
Flight control
resistance
Erroneous engine
status
Abnormal engine noise
Possible Causes
Propeller installed incorrectly
♦
Idle RPM too low
♦
Carb. sycronization out of balance
♦
Engine suspension loose
♦
Carburetor malfunction
♦
Ignition malfunction
♦
Loose fasteners
♦
Loose baggage
♦
Loose electrical connection
♦
Exposure to contamination
♦
Failing protective coating
♦
Unlike metals exposed to moisture
♦
Insufficient lubrication
♦
Control surface hinge axis not aligned
♦
Failing control system components
♦
Improper control system adjustments
♦
Malfunctioning sensor
♦
Loose connection
♦
Malfunctioning EMS
♦
Damaged or leaking exhaust system
♦
Open passage in firewall
♦
16-2
Rev.1
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