310T Exam - Engine and Supporting Systems Exam
2026/2027 – Comprehensive A+ Graded Practice
Questions with Answers
1. What would be indicated by engine oil contaminated with
coolant?
a. Cracked dry liner.
b. Leaking liner O-rings.
c. Leaking oil cooler core.
d. Cracked liner counter-bore. - ✔✔ANSWER ✔✔-b. Leaking
liner O-rings.
2. What will cause excessive crankcase blow by?
a. Worn oil control rings.
b. Excessive engine speed.
,c. Worn compression rings.
d. A plugged crankcase filter. - ✔✔ANSWER ✔✔-c. Worn
compression rings.
3. What would be the case of a failed cylinder head gasket?
a. Rolled liner O-rings.
b. Cracked cylinder head.
c. Insufficient liner height.
d. Turbocharger waste-gate stuck open. - ✔✔ANSWER ✔✔-c.
Insufficient liner height.
4. What would indicate a faulty vacuum valve in the radiator
cap?
a. Engine overheating.
b. Collapsed radiator hose.
c. Extended warm up time.
d. Overfilled coolant reservoir. - ✔✔ANSWER ✔✔-b. Collapsed
radiator hose.
5. What component is leaking when the engine oil is found in
the coolant?
,a. Injector cups.
b. Oil cooler core.
c. After cooler core.
d. Cylinder liner O-rings. - ✔✔ANSWER ✔✔-b. Oil cooler core.
6. What would indicate that the engine oil pump regulating
valve is stuck open?
a. Increased oil pressure.
b. Decreased oil pressure.
c. Increased oil consumption.
d. Decreased oil consumption. - ✔✔ANSWER ✔✔-b. Decreased
oil pressure.
7. What will cause a diesel engine to run rough and stall?
a. Poor fuel quality.
b. A plugged return line.
c. Air in the fuel system.
d. Low transfer pump pressure.
54 - ✔✔ANSWER ✔✔-c. Air in the fuel system.
8. What is the cause of low fuel transfer pump pressure?
, a. Plugged fuel filter.
b. Return line restriction.
c. Leaking fuel tank vent.
d. Regulating valve stuck closed. - ✔✔ANSWER ✔✔-a. Plugged
fuel filter.
9. Which will cause a diesel engine to have low power output?
a. Cracked intercooler.
b. Excessive turbocharger speed.
c. Leaking turbocharger exhaust outlet.
d. Turbocharger waste-gate valve stuck closed. - ✔✔ANSWER
✔✔-a. Cracked intercooler.
10. What must be used on an engine equipped with a DPF
filter?
a. Fuel lubricity additive.
b. Low sulfur Diesel fuel.
c. 5% Bio-Diesel/Ethanol blend.
d. Ultra low sulfur diesel fuel. - ✔✔ANSWER ✔✔-d. Ultra low
sulfur diesel fuel
2026/2027 – Comprehensive A+ Graded Practice
Questions with Answers
1. What would be indicated by engine oil contaminated with
coolant?
a. Cracked dry liner.
b. Leaking liner O-rings.
c. Leaking oil cooler core.
d. Cracked liner counter-bore. - ✔✔ANSWER ✔✔-b. Leaking
liner O-rings.
2. What will cause excessive crankcase blow by?
a. Worn oil control rings.
b. Excessive engine speed.
,c. Worn compression rings.
d. A plugged crankcase filter. - ✔✔ANSWER ✔✔-c. Worn
compression rings.
3. What would be the case of a failed cylinder head gasket?
a. Rolled liner O-rings.
b. Cracked cylinder head.
c. Insufficient liner height.
d. Turbocharger waste-gate stuck open. - ✔✔ANSWER ✔✔-c.
Insufficient liner height.
4. What would indicate a faulty vacuum valve in the radiator
cap?
a. Engine overheating.
b. Collapsed radiator hose.
c. Extended warm up time.
d. Overfilled coolant reservoir. - ✔✔ANSWER ✔✔-b. Collapsed
radiator hose.
5. What component is leaking when the engine oil is found in
the coolant?
,a. Injector cups.
b. Oil cooler core.
c. After cooler core.
d. Cylinder liner O-rings. - ✔✔ANSWER ✔✔-b. Oil cooler core.
6. What would indicate that the engine oil pump regulating
valve is stuck open?
a. Increased oil pressure.
b. Decreased oil pressure.
c. Increased oil consumption.
d. Decreased oil consumption. - ✔✔ANSWER ✔✔-b. Decreased
oil pressure.
7. What will cause a diesel engine to run rough and stall?
a. Poor fuel quality.
b. A plugged return line.
c. Air in the fuel system.
d. Low transfer pump pressure.
54 - ✔✔ANSWER ✔✔-c. Air in the fuel system.
8. What is the cause of low fuel transfer pump pressure?
, a. Plugged fuel filter.
b. Return line restriction.
c. Leaking fuel tank vent.
d. Regulating valve stuck closed. - ✔✔ANSWER ✔✔-a. Plugged
fuel filter.
9. Which will cause a diesel engine to have low power output?
a. Cracked intercooler.
b. Excessive turbocharger speed.
c. Leaking turbocharger exhaust outlet.
d. Turbocharger waste-gate valve stuck closed. - ✔✔ANSWER
✔✔-a. Cracked intercooler.
10. What must be used on an engine equipped with a DPF
filter?
a. Fuel lubricity additive.
b. Low sulfur Diesel fuel.
c. 5% Bio-Diesel/Ethanol blend.
d. Ultra low sulfur diesel fuel. - ✔✔ANSWER ✔✔-d. Ultra low
sulfur diesel fuel
