310T Engine Systems Final Exam
Questions and All Correct Answers
2025-2026 Updated.
What is the ratio between exhaust temperatures to air intake temperature
a) 2:1
b) 4:1
c) 3:1
d) 1:1 - Answer c) 3:1
JWACs are capable of reducing air intake temperatures by ____________.
a) 75°F
b) 50°F
c) 100°F
d) 125°F - Answer c) 100°F
ATAAC system cooling is affected by which variable?
a) Surface area
b) Road speed
c) Ambient temperature
d) All are correct - Answer d) All are correct
There should not be a pressure drop of more than _______, measured at ATAAC inlet and
outlet.
a) 1 lb
b) 10 lbs
c) 5 lbs
d) 3 lbs - Answer d) 3 lbs
When performing a restriction test of an ATAAC, the test needs to be performed at
____________.
,a) rated HP
b) idle
c) full load
d) high idle - Answer c) full load
After a catastrophic turbocharger failure, the ATAAC should be ____________.
a) flushed to remove debris
b) restriction tested
c) pressure tested
d) All are correct - Answer d) All are correct
The temperatures and pressures exerted on ATAACs require the technician to use __________
to properly secure the pressure hoses.
a) gear clamps
b) wire ties
c) mechanic's wire
d) spring operated clamps - Answer d) spring operated clamps
Benefits of charge air cooling has been reported to improve fuel economy by ________ percent.
a) 5%
b) 20%
c) 15%
d) 10% - Answer a) 5%
What is the acceptable pressure drop allowed across a CAC when performing a leakage test?
a) Refer to manufacturer's specifications
b) 10 psi in 15 seconds
c) 10 psi in 10 seconds
d) 15 psi in 20 seconds - Answer a) Refer to manufacturer's specifications
, An engine's piston is found to be cracked at the edge of the combustion bowl. What could cause
such a failure?
a) Externally restricted CAC
b) Restricted air hose
c) Plugged exhaust
d) Overfueling injector - Answer a) Externally restricted CAC
What is being evaluated when, under load, the intake manifold pressure and turbocharger
outlet pressure are compared?
a) External restriction of a CAC
b) CAC efficiency
c) Internal restriction of a charge air cooler (CAC)
d) CAC leaks - Answer c) Internal restriction of a charge air cooler (CAC)
Under what conditions does EGR gas pass through the CAC on a high-pressure cooled EGR
system?
a) EGR gas never passes through the CAC
b) When the EGR valve is open and the engine is under load
c) Only at idle
d) When the EGR bypass valve is opened - Answer a) EGR gas never passes through the CAC
Which of the following statements is true about CACs?
a) CACs enable the use of higher cylinder fueling rates.
b) Any crack in the CAC is not acceptable and leads to low-power complaints.
c) CACs reduce formation of particulates.
d) Adding a CAC can significantly increase engine power output. - Answer a) CACs enable the
use of higher cylinder fueling rates.
What is the last thing to do after servicing the cooling system of an engine with jacket water
after cooling (JWAC)?
a) Pressurize the cooling system to check the JWAC for leaks.
Questions and All Correct Answers
2025-2026 Updated.
What is the ratio between exhaust temperatures to air intake temperature
a) 2:1
b) 4:1
c) 3:1
d) 1:1 - Answer c) 3:1
JWACs are capable of reducing air intake temperatures by ____________.
a) 75°F
b) 50°F
c) 100°F
d) 125°F - Answer c) 100°F
ATAAC system cooling is affected by which variable?
a) Surface area
b) Road speed
c) Ambient temperature
d) All are correct - Answer d) All are correct
There should not be a pressure drop of more than _______, measured at ATAAC inlet and
outlet.
a) 1 lb
b) 10 lbs
c) 5 lbs
d) 3 lbs - Answer d) 3 lbs
When performing a restriction test of an ATAAC, the test needs to be performed at
____________.
,a) rated HP
b) idle
c) full load
d) high idle - Answer c) full load
After a catastrophic turbocharger failure, the ATAAC should be ____________.
a) flushed to remove debris
b) restriction tested
c) pressure tested
d) All are correct - Answer d) All are correct
The temperatures and pressures exerted on ATAACs require the technician to use __________
to properly secure the pressure hoses.
a) gear clamps
b) wire ties
c) mechanic's wire
d) spring operated clamps - Answer d) spring operated clamps
Benefits of charge air cooling has been reported to improve fuel economy by ________ percent.
a) 5%
b) 20%
c) 15%
d) 10% - Answer a) 5%
What is the acceptable pressure drop allowed across a CAC when performing a leakage test?
a) Refer to manufacturer's specifications
b) 10 psi in 15 seconds
c) 10 psi in 10 seconds
d) 15 psi in 20 seconds - Answer a) Refer to manufacturer's specifications
, An engine's piston is found to be cracked at the edge of the combustion bowl. What could cause
such a failure?
a) Externally restricted CAC
b) Restricted air hose
c) Plugged exhaust
d) Overfueling injector - Answer a) Externally restricted CAC
What is being evaluated when, under load, the intake manifold pressure and turbocharger
outlet pressure are compared?
a) External restriction of a CAC
b) CAC efficiency
c) Internal restriction of a charge air cooler (CAC)
d) CAC leaks - Answer c) Internal restriction of a charge air cooler (CAC)
Under what conditions does EGR gas pass through the CAC on a high-pressure cooled EGR
system?
a) EGR gas never passes through the CAC
b) When the EGR valve is open and the engine is under load
c) Only at idle
d) When the EGR bypass valve is opened - Answer a) EGR gas never passes through the CAC
Which of the following statements is true about CACs?
a) CACs enable the use of higher cylinder fueling rates.
b) Any crack in the CAC is not acceptable and leads to low-power complaints.
c) CACs reduce formation of particulates.
d) Adding a CAC can significantly increase engine power output. - Answer a) CACs enable the
use of higher cylinder fueling rates.
What is the last thing to do after servicing the cooling system of an engine with jacket water
after cooling (JWAC)?
a) Pressurize the cooling system to check the JWAC for leaks.
