EETC - Equipment & Engine Training Council Cooling Systems and Thermal Management Questions and Answers Flashcards

What is the primary function of the thermostat in a small engine cooling system?

Answer: Regulate coolant flow to maintain operating temperature

The thermostat regulates coolant flow by opening and closing based on coolant temperature to keep the engine within its optimal operating range.

Which type of cooling system uses fins on the cylinder and head to dissipate heat directly into the surrounding air?

Answer: Air cooling

Air-cooled engines use cast fins on the cylinder and head to maximize surface area and radiate heat directly into the airflow around the engine.

A technician notices white steam and a sweet smell from an air-cooled engine. What is the most likely cause?

Answer: Blown head gasket allowing coolant into combustion chamber

A sweet smell and white steam indicate coolant entering the combustion chamber, which is a classic symptom of a blown head gasket.

What is cavitation in a liquid-cooled engine water pump?

Answer: Formation and collapse of vapor bubbles that erode pump surfaces

Cavitation occurs when low pressure causes coolant to vaporize, forming bubbles that collapse violently and erode the pump impeller and housing.

Which coolant additive prevents corrosion and scale buildup in liquid-cooled engine passages?

Answer: Corrosion inhibitor package in antifreeze

Modern antifreeze formulations include a corrosion inhibitor package that protects metal surfaces and prevents scale deposits in cooling passages.

What symptom indicates a plugged or clogged cooling fin on an air-cooled engine?

Answer: Engine overheats and may shut down via thermal protection

Clogged cooling fins restrict airflow and heat dissipation, causing the engine to overheat and potentially trigger its thermal protection shutdown.