310S Engine Systems and Repair 5

Question 1

What is the purpose of the thermostat bypass circuit in an engine cooling system?

Accepted Answer

To circulate coolant within the engine block before the thermostat opens

Answer

To allow coolant to flow to the heater core at all times

Answer

To prevent the radiator from overheating

Answer

To drain the cooling system for service

Question 2

An engine has low oil pressure at idle but normal pressure at higher RPM. What is the most likely cause?

Accepted Answer

Worn oil pump or excessive bearing clearances

Answer

Clogged oil filter

Answer

Faulty oil pressure sending unit

Answer

Overfilled oil level

Question 3

What is the correct sequence for tightening cylinder head bolts?

Accepted Answer

Centre-outward spiral pattern in multiple steps

Answer

Outside-in pattern in a single step

Answer

Alternating corners in two steps

Answer

Any order as long as final torque is correct

Question 4

What causes piston ring flutter?

Accepted Answer

Engine RPM exceeding the ring's ability to maintain contact with the cylinder wall

Answer

Too much piston-to-wall clearance

Answer

Incorrect ring compressor use during installation

Answer

Low-quality engine oil

Question 5

What is the purpose of the oil squirter (piston cooling jet) found in some engines?

Accepted Answer

To spray oil onto the underside of the piston for cooling

Answer

To lubricate the cylinder walls

Answer

To increase oil pressure at high RPM

Answer

To clean carbon deposits from the piston crown

Question 6

What does a cylinder power balance test determine?

Accepted Answer

The relative contribution of each cylinder to overall engine power

Answer

The compression ratio of each cylinder

Answer

The fuel injector flow rate for each cylinder

Answer

The ignition timing for each cylinder