Engine Performance Mid Term Exam
Questions & Answers (Grade A+)
1. What does excessive white smoke from the tail pipe indicate and
what could be the cause? -
correct answer ✅Light steam is normal but excessive white smoke
is a sign of coolant burning in the combustion chamber. Could be
caused by a leaking head gasket or crack in the cylinder head or
engine block
This noise is not affected by load, and sound like a double knock. If
you disconnect one spark plug at a time when the engine is running
the noise does not go away. -
correct answer ✅Piston Pin Knock
This noise is most noticeable when the engine is cold and goes
away as the engine warms up. -
correct answer ✅Piston Slap
This noise is load sensitive. If you disconnect one spark plug at a
time when the engine is running the noise goes away on the
defective cylinder -
correct answer ✅Rod bearing noise
,Engine Performance Mid Term Exam
Questions & Answers (Grade A+)
What should the first puff reading indicate if the compression is
good? -
correct answer ✅At least ½ the final puff
What reading is good?
What reading is acceptable?
What reading is poor?
what reading is a definite problem? -
correct answer ✅good: Equal or less than 10%
acceptable: Greater than 10% but less than 20%
poor: 20% to 30%
definite problem: Greater than 30%
Which cylinder is the bad one when performing a power balance
test, the cylinder that drops the most RPM or the least RPM. -
correct answer ✅The cylinder with the least RPM drop
What should the vacuum be at?
Cranking:
Idle: -
correct answer ✅cranking: 2.5 to 6in hg.
, Engine Performance Mid Term Exam
Questions & Answers (Grade A+)
idle: 17 to 21 in. Hg.
What is the acceptable amount of back pressure?
At Idle:
At 2500 RPM: -
correct answer ✅At Idle; < 1.5 psi
At 2500 RPM; < 2.5 psi
What is the normal coolant temperature? -
correct answer ✅200 to 220 degrees Fahrenheit
What is the typical release pressure of the fuel tank pressure cap? -
correct answer ✅over 1.5 psi to 2 psi (2.5psi ok)
What is the typical release vacuum of the fuel tank pressure cap? -
correct answer ✅.15 psi to .3 psi
or 1 to 2 kpa
Ford use an _______________ _____________ to shut off the fuel
pump during a sudden impact. It is located in the _____________
area. -
Questions & Answers (Grade A+)
1. What does excessive white smoke from the tail pipe indicate and
what could be the cause? -
correct answer ✅Light steam is normal but excessive white smoke
is a sign of coolant burning in the combustion chamber. Could be
caused by a leaking head gasket or crack in the cylinder head or
engine block
This noise is not affected by load, and sound like a double knock. If
you disconnect one spark plug at a time when the engine is running
the noise does not go away. -
correct answer ✅Piston Pin Knock
This noise is most noticeable when the engine is cold and goes
away as the engine warms up. -
correct answer ✅Piston Slap
This noise is load sensitive. If you disconnect one spark plug at a
time when the engine is running the noise goes away on the
defective cylinder -
correct answer ✅Rod bearing noise
,Engine Performance Mid Term Exam
Questions & Answers (Grade A+)
What should the first puff reading indicate if the compression is
good? -
correct answer ✅At least ½ the final puff
What reading is good?
What reading is acceptable?
What reading is poor?
what reading is a definite problem? -
correct answer ✅good: Equal or less than 10%
acceptable: Greater than 10% but less than 20%
poor: 20% to 30%
definite problem: Greater than 30%
Which cylinder is the bad one when performing a power balance
test, the cylinder that drops the most RPM or the least RPM. -
correct answer ✅The cylinder with the least RPM drop
What should the vacuum be at?
Cranking:
Idle: -
correct answer ✅cranking: 2.5 to 6in hg.
, Engine Performance Mid Term Exam
Questions & Answers (Grade A+)
idle: 17 to 21 in. Hg.
What is the acceptable amount of back pressure?
At Idle:
At 2500 RPM: -
correct answer ✅At Idle; < 1.5 psi
At 2500 RPM; < 2.5 psi
What is the normal coolant temperature? -
correct answer ✅200 to 220 degrees Fahrenheit
What is the typical release pressure of the fuel tank pressure cap? -
correct answer ✅over 1.5 psi to 2 psi (2.5psi ok)
What is the typical release vacuum of the fuel tank pressure cap? -
correct answer ✅.15 psi to .3 psi
or 1 to 2 kpa
Ford use an _______________ _____________ to shut off the fuel
pump during a sudden impact. It is located in the _____________
area. -
