ASE Practice Test 3: Diagnosis and Repair of Lubrication and
Cooling Systems
Technician A says that before installing an oil pump, it should be primed with clean engine oil. Technician
B says that before installing an oil pump, the position of the pickup screen should be checked to make
sure it fits closely to the bottom of the oil pan. Who is right? - correct answer ✔✔The correct answer is
C, both technicians are right.
~The oil pump should be filled with oil during engine reassembly to prevent it from cavitating or sucking
air during engine start-up. To prevent the pickup from sucking air and subsequent oil starvation and
engine damage, make sure the pickup screen is positioned close to the bottom of the oil pan to ensure it
is always submerged in oil.
All of the following can cause low oil pressure EXCEPT:
A. diluted engine oil
B. worn pistons
C. excessive bearing clearance
D. clogged oil pump pickup - correct answer ✔✔The correct answer is B.
~Worn pistons can cause noise and accelerate ring and bore wear, but would not cause low oil pressure.
Diluted oil, excessive bearing clearance and a clogged pump pickup can all cause low oil pressure.
Technician A says that the thermostat controls maximum engine temperature. Technician B says if the
engine continously runs hot, install a cooler thermostat. Who is right? - correct answer ✔✔The correct
answer is D, neither technician is right.
~The thermostat's function is to allow the engine to come to operating temperature quickly and them
maintain a minimum operating temperature. The PCM bases fuel mixture, ignition timing, EGR operation
and other functions in part on input regarding coolant temperature. Only the correct heat range
thermostat should be installed. If the thermostat is good and the engine runs hot, another problem
exists.
All of the following could cause an engine to overheat EXCEPT:
A. defective fan clutch
Cooling Systems
Technician A says that before installing an oil pump, it should be primed with clean engine oil. Technician
B says that before installing an oil pump, the position of the pickup screen should be checked to make
sure it fits closely to the bottom of the oil pan. Who is right? - correct answer ✔✔The correct answer is
C, both technicians are right.
~The oil pump should be filled with oil during engine reassembly to prevent it from cavitating or sucking
air during engine start-up. To prevent the pickup from sucking air and subsequent oil starvation and
engine damage, make sure the pickup screen is positioned close to the bottom of the oil pan to ensure it
is always submerged in oil.
All of the following can cause low oil pressure EXCEPT:
A. diluted engine oil
B. worn pistons
C. excessive bearing clearance
D. clogged oil pump pickup - correct answer ✔✔The correct answer is B.
~Worn pistons can cause noise and accelerate ring and bore wear, but would not cause low oil pressure.
Diluted oil, excessive bearing clearance and a clogged pump pickup can all cause low oil pressure.
Technician A says that the thermostat controls maximum engine temperature. Technician B says if the
engine continously runs hot, install a cooler thermostat. Who is right? - correct answer ✔✔The correct
answer is D, neither technician is right.
~The thermostat's function is to allow the engine to come to operating temperature quickly and them
maintain a minimum operating temperature. The PCM bases fuel mixture, ignition timing, EGR operation
and other functions in part on input regarding coolant temperature. Only the correct heat range
thermostat should be installed. If the thermostat is good and the engine runs hot, another problem
exists.
All of the following could cause an engine to overheat EXCEPT:
A. defective fan clutch
