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ALBERTA HEAVY DUTY EQUIPMENT
TECHNICIAN RED SEAL EXAM PRACTICE
QUESTIONS AND CORRECT ANSWERS
**1. What will cause blue exhaust smoke?**
A. Leaking injector nozzle
B. Leaking injector cup
C. Excessive valve lash
D. Restricted air intake
**Correct answer:** A
**Rationale:** Blue exhaust smoke indicates that engine oil is
being burned in the combustion chamber. A leaking injector
nozzle can allow oil to enter the combustion chamber, resulting
in blue smoke. A leaking injector cup typically causes fuel
contamination in the coolant or oil, while excessive valve lash
affects valve timing and performance .
**2. What will cause a sudden drop in oil pressure?**
A. Worn oil pump
B. Worn main bearings
C. Regulating valve stuck open
D. Regulating valve stuck closed
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**Correct answer:** C
**Rationale:** A pressure regulating valve stuck in the open
position allows oil to bypass the main galleries and return
directly to the sump, causing an immediate and significant drop
in system pressure. Worn pumps or bearings cause gradual
pressure loss .
**3. What will cause engine overheating if the top radiator hose
is cold and the bottom radiator hose is hot?**
A. Thermostat stuck open
B. A blocked bypass circuit
C. Thermostat is stuck closed
D. Radiator core is leaking
**Correct answer:** C
**Rationale:** A cold upper hose indicates that hot coolant is
not flowing from the engine into the radiator. This is a classic
symptom of a thermostat stuck in the closed position,
preventing coolant circulation through the radiator. The lower
hose remains hot because the water pump is still circulating hot
coolant within the engine block .
**4. What will cause seized turbocharger bearings?**
A. Plugged drain line
B. Restricted air intake
C. Insufficient cool down time
ALBERTA HEAVY DUTY EQUIPMENT
TECHNICIAN RED SEAL EXAM PRACTICE
QUESTIONS AND CORRECT ANSWERS
**1. What will cause blue exhaust smoke?**
A. Leaking injector nozzle
B. Leaking injector cup
C. Excessive valve lash
D. Restricted air intake
**Correct answer:** A
**Rationale:** Blue exhaust smoke indicates that engine oil is
being burned in the combustion chamber. A leaking injector
nozzle can allow oil to enter the combustion chamber, resulting
in blue smoke. A leaking injector cup typically causes fuel
contamination in the coolant or oil, while excessive valve lash
affects valve timing and performance .
**2. What will cause a sudden drop in oil pressure?**
A. Worn oil pump
B. Worn main bearings
C. Regulating valve stuck open
D. Regulating valve stuck closed
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**Correct answer:** C
**Rationale:** A pressure regulating valve stuck in the open
position allows oil to bypass the main galleries and return
directly to the sump, causing an immediate and significant drop
in system pressure. Worn pumps or bearings cause gradual
pressure loss .
**3. What will cause engine overheating if the top radiator hose
is cold and the bottom radiator hose is hot?**
A. Thermostat stuck open
B. A blocked bypass circuit
C. Thermostat is stuck closed
D. Radiator core is leaking
**Correct answer:** C
**Rationale:** A cold upper hose indicates that hot coolant is
not flowing from the engine into the radiator. This is a classic
symptom of a thermostat stuck in the closed position,
preventing coolant circulation through the radiator. The lower
hose remains hot because the water pump is still circulating hot
coolant within the engine block .
**4. What will cause seized turbocharger bearings?**
A. Plugged drain line
B. Restricted air intake
C. Insufficient cool down time
