Auto 140 Mid-term Review Notes

Question 1

Which part of the engine controls the way it breaths?

Answer 1

Intake and Exhaust Manifold?
Valve Train?
Intake Valve?
Engine Displacement?

Question 2

Other than worn out Piston Rings what other things cause Oil Consumption Problems?

Answer 2

Bad Valve Guides or Seals
Piston Rings
Worn Compression Rings
New Valve Job
Excessive Rod Bearing Clearance
Incorrect Engine Oil Dipstick
Plugged Cylinder Head Drainback Hole
Leaking Intake Manifold Gasket
Clogged PCV (Positive Crankcase Ventilation) Valve

Question 3

What is likely the Problem if you have a Rod Knock developing?

Answer 3

Excessive clearance at a connecting rod journal.

Question 4

Flexplate or Flywheel, which one goes with which type of transmission?

Answer 4

Flywheels are found on vehicles equipped with manual transmissions.
Flexplates are found on vehicles equipped with automatic transmissions.

Question 5

Is it a good idea to let the engine cool down before removing the head?

Answer 5

Yes…

Question 6

Cleaning with Acids removes?

Answer 6

Rust and Scale

Question 7

Cleaning with bases (Alkaline) removes?

Answer 7

Grease

Question 8

Switching to aluminum heads requires?

Answer 8

Lowering Compression Ratio

Question 9

Springs that overheat?

Answer 9

not sure

Question 10

How many degrees is a complete 4 stroke cycle?

Answer 10

720 degrees for the crankshaft

Question 11

Which engines fire 90 degrees apart, 120, and 180?

Answer 11

4 Cylinder, 180 degrees
6 Cylinder, 120 degrees
8 Cylinder, 90 degrees

Question 12

What is the Ideal air fuel mixture in a combustion engine?

Answer 12

The stoichiometric air–fuel mixture is about 14.7:1
(i.e. for every one gram of fuel, 14.7 grams of air are required)

Question 13

Detonation by overly lean mixture?

Question 14

Why is the “i” head better?

Answer 14

The valves can stay open longer and there is more valve clearance.

Question 15

If you short out the cylinder (remove the spark plug from the combustion chamber) will Rod Knock get quieter or louder?

Answer 15

Quieter

Question 16

If you short out the cylinder (remove the spark plug from the combustion chamber) will Piston Slap get quieter or louder?

Answer 16

Louder

Question 17

An air fuel mixture that’s too lean does what kind of damage?

Question 18

What can happen if you have too much fuel in the combustion chamber?

Answer 18

It washes down the cylinder walls

Question 19

What does carbon build up on a valve increase in a combustion chamber?

Answer 19

Increases the compression ratio

Question 20

The less room there is in a chamber the higher the _______. The more room there is the lower_______ there is.

Answer 20

Compression

Question 21

Slow Vacuum

Answer 21

Retarded Timing

Question 22

How much can a spring be out of square.

Question 23

Explain ignition in a Diesel Engine.

Question 24

What is the difference between a short block and a long block.

Question 25

List some causes of engine overheating.

Answer 25

Stuck Thermostat
Blown Head Gasket
Plugged Exhaust
Bad water Pump
Plugged Radiator
Retarded Timing

Question 26

List the steps to perform a Compression check.

Answer 26

Remove spark plugs
Disable spark
Pull Fuel pump Fuse
Screw in the Compression tester that fits
Crank for the same amount of times for each cylinder
Record the reading