1. Which of the following SAE multigrade oils would likely be recommended by
most highway diesel engine OEMs for year-round use in North America?   

2. Which of the following API classifications indicates that the oil is formulated for diesel engines meeting 2010 emissions standards?


3. What conditions could result from a high crankcase oil level?

Lube oil aeration, oil pressure gauge fluctuations, and friction bearing damage (all above)

4. When investigating a low oil pressure complaint, which of the following should be performed first?

Check the crankcase oil level.

5. A full flow oil filter has become completely plugged. What is the likely outcome if the engine is running?

A bypass valve diverts the oil around the filter.

Engine oil temperatures are higher than coolant temperatures.

7. Which type of oil pump is most commonly used in current highway diesel engines?
External gear

8. Which of the following is usually the preferred OEM method of testing an oil cooler bundle?
Vacuum test

9. When interpreting a used engine oil analysis profile, which of the following conditions would be most likely to cause high silicon levels?
Air cleaner perforation

10.Which of the following correctly identifies the source of diesel engine oil?
crude petroleum

11. Engine oil service classifications are standardized by which of the following organizations?


12. Technician A states that the operating temperature of an engine oil should be within 5°F of that of the engine coolant operating temperature. Technician B states that engine oil temperatures are probably a more accurate means of assessing actual engine operating temperature than the coolant temperature reading. Who is correct?

Tech B only

13. An auxiliary oil pump designed to feed oil to the lubrication circuit on a vehicle that operates at extreme working angles is known as a(n):
gerator pump

14. Oil that has a milky, clouded appearance is probably contaminated with:

Engine coolant

15. Which of the following statements best describes viscosity?
Resistance to flow

16. Technician A states that an oil cooler operates by having coolant pumped through the bundle tubes and oil circulated around the tubes. Technician B states that a leaking oil cooler core must always be replaced. Who is correct?

17. Technician A states that 15W-40 is the most commonly used truck engine oil. Technician B states that 15W-40 oil is not an appropriate all-season oil, because winter temperatures are often much lower than the SAE recommended ambient temperature window for this oil. Who is correct?

18. Technician A states that the device used to signal oil pressure values to the ECM on most electronically managed engines uses a variable capacitance operating principle. Technician B states that an oil pressure sensor usually requires a V-Ref source from the engine ECM. Who is correct?

19. Technician A states that an engine equipped with EGR and DPF must use API CJ-4 engine oil. Technician B states that engines manufactured before 2007 may use API CK-4 engine oil. Who is correct?

20. A diesel engine dash oil pressure gauge displays low and fluctuating oil pressure values when the vehicle is operated. Technician A states that this could be caused by low engine oil level. Technician B states that this could be caused by high engine oil level. Who is correct?

Low oil can cause low oil pressure and high oil can cause high oil pressure

How often should you change the oil in your truck?

25K-50K miles

  • Driving Habits: If you push your vehicle too hard, drive it on steep inclines frequently, or consistently drive on rough surfaces, your efficiency will drop and your oil will need to be changed more frequently.
  • Driving Conditions: Driving through severe heat or severe cold for hundreds of miles impacts your oil. It will loose its thickness in heat, and becomes thicker in cold weather. These both have adverse affects on your engine, and could therefore force an oil change sooner than planned.