🔍 Key Concepts

• how piston movement changes when there is no air load (unloaded compressor) • typical symptoms of valve problems vs lubrication problems vs loose components • which condition would create an intermittent mechanical impact sound rather than a hiss or squeal

💭 Think About

• Think about what parts inside a compressor actually "knock" against each other when there is extra clearance or looseness. • Consider how an unloaded compressor (little or no pressure resistance) changes the forces on the piston and connecting parts. • For each choice, imagine the sound you would expect: would it be a sharp knock, a continuous hiss, or a squeal/overheating symptom?

✅ Before You Answer

• Be clear on the difference between a mechanical impact noise (knock) and an airflow/pressure noise (hiss or whoosh). • Ask which option would be most affected when the compressor is unloaded versus loaded. • Verify which condition is most likely to get worse if the moving part has excess clearance or looseness.