An engine noise sounds like a knock at the side of the engine that is louder when the engine is cold and goes away or is reduced when the engine reaches operating temperature. Which of the following is the MOST likely cause?

ASE identifies Engine Repair as an individual service area for certification. The engine repair service area involves the following components:

- General Engine Diagnosis
- Cylinder Head and Valve Train Diagnosis and Repair
- Engine Block Diagnosis and Repair
- Lubrication and Cooling Systems Diagnosis and Repair
- Fuel, Electrical, Ignition and Exhaust Systems Diagnosis and Repair.