Automotive Technology Flashcards

What is the primary function of the crankshaft in an internal combustion engine?

Answer: Convert reciprocating piston motion into rotational motion

The crankshaft converts the up-and-down (reciprocating) motion of the pistons into the rotational motion that drives the drivetrain.

Which gasket seals the combustion chamber between the cylinder head and the engine block?

Answer: Head gasket

The head gasket seals the joint between the cylinder head and engine block, preventing combustion gases, coolant, and oil from mixing.

What does the acronym 'OHC' stand for in engine design?

Answer: Overhead Camshaft

OHC stands for Overhead Camshaft, meaning the camshaft is located in the cylinder head above the valves rather than in the block.

What is the purpose of the PCV (Positive Crankcase Ventilation) valve?

Answer: Recirculate crankcase blow-by gases back into the intake manifold

The PCV valve routes unburned gases from the crankcase back into the intake manifold to be burned in the engine, reducing emissions.

When performing a compression test and one cylinder shows significantly lower compression than the others, which component is most likely worn?

Answer: Piston rings or cylinder wall

Worn piston rings or a scored cylinder wall allow combustion gases to bypass the piston, resulting in low compression in that cylinder.

Which sensor in the exhaust system measures oxygen content to help the ECM maintain the correct air-fuel ratio?

Answer: Oxygen (O2) sensor

The oxygen sensor monitors exhaust oxygen levels and sends signals to the ECM to adjust fuel trim for a proper stoichiometric mixture.

What is the purpose of the timing belt or timing chain in an engine?

Answer: Synchronize the crankshaft and camshaft rotation

The timing belt or chain synchronizes the crankshaft and camshaft so that valves open and close at the correct time relative to piston position.