EETC - Equipment & Engine Training Council Compact Diesel Engine Repair Questions and Answers

Question 1

A compact diesel engine is difficult to start, especially in cold weather, and produces excessive white smoke upon starting. Which of the following is the MOST likely cause?

Accepted Answer

Malfunctioning glow plugs

Answer

Clogged fuel filter

Answer

Low engine compression

Answer

A faulty starter motor

Question 2

When testing a common rail fuel injector, a technician performs a return flow (back-leak) test. What is the primary purpose of this test?

Accepted Answer

To identify excessive internal leakage within the injector.

Answer

To measure the volume of fuel delivered to the cylinder.

Answer

To check for external fuel leaks around the injector body.

Answer

To verify the electrical resistance of the injector solenoid.

Question 3

The primary function of a turbocharger's wastegate on a compact diesel engine is to:

Accepted Answer

Limit the maximum boost pressure to protect the engine.

Answer

Increase exhaust gas temperature for DPF regeneration.

Answer

Cool the compressed intake air before it enters the engine.

Answer

Reduce engine noise during high RPM operation.

Question 4

A technician is servicing a compact diesel engine equipped with a Diesel Particulate Filter (DPF). The operator reports frequent DPF warning lights and poor performance, primarily during low-speed, stop-and-go operation. What is the most likely reason for these symptoms?

Accepted Answer

Failure of the passive regeneration process.

Answer

The engine oil is of the wrong viscosity.

Answer

A cracked exhaust manifold.

Answer

The fuel's cetane rating is too high.

Question 5

When using a multimeter to test the resistance of a glow plug, what would a reading of 'OL' (Over Limit) or infinity most likely indicate?

Accepted Answer

An open circuit within the glow plug element.

Answer

A short circuit to ground.

Answer

The glow plug is functioning correctly.

Answer

The engine block is not properly grounded.

Question 6

Which of the following is a critical first step when diagnosing a 'crank, no start' condition on a modern compact diesel engine?

Accepted Answer

Checking for diagnostic trouble codes (DTCs) with a scan tool.

Answer

Immediately performing an engine compression test.

Answer

Replacing the fuel filter and bleeding the system.

Answer

Testing the output of the starter motor.