Deck 13: Engine Sealing and Reassembly

Question 1

Tightening of a bolt should be done with an impact wrench followed by a torque wrench.

Answer 1

False

Question 2

The proper engine break-in procedure is a test run at ______.

A)constant 30 mph (48 km/h)
B)10 mph (16 km/h)and acceleration to 30 mph (48 km/h)
C)constant 60 mph (96 km/h)highway speed
D)30 mph (48 km/h)and acceleration to 50 mph (80 km/h)

Answer 2

D

Question 3

All head bolts in an engine are the same length.

Answer 3

False

Question 4

The shop manual should have a picture of the head bolt tightening sequence. However, if there is no shop manual or technical data available, what would the best tightening sequence be?

A)Go from left to right all of the top row (intake side)first, then tighten all of the bottom row (exhaust)bolts right to left
B)Go from left to right all of the bottom row bolts (exhaust side)first, then tighten all of the top row (intake)bolts right to left
C)Go in a circular pattern beginning in the center and ending on the outboard ends
D)Go in a circular pattern working from the outside toward the center

Question 5

Technician A says cork gaskets are used on most modern engines for valve cover and oil pan gaskets. Technician B says cork gaskets will weep some of the fluid they are sealing. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 6

When lubrication of a fastener is recommended prior to installation, ______.

A)add the lubricant to the bolt hole
B)apply the lubricant to the bolt threads
C)Both A and B
D)Neither A nor B

Question 7

Gasket sealants should be used on all gasket installations.

Question 8

After the break-in period, the cylinder head and intake manifold bolts may need to be retorqued.

Question 9

Elasticity means that a bolt can be stretched or compressed.

Question 10

A gasket installed upside down or reversed may cause loss of oil pressure, overheating, and engine failure.

Question 11

What should be done to correct bolt holes in the block that are pulled up (raised)?

A)The threads should be cleaned with a bottoming tap
B)The bolt holes should be tapered at the surface by chamfering
C)The threads should be cleaned with a bottoming tap and the bolt holes should be tapered at the surface by chamfering.
D)None of the answers is correct.

Question 12

What keeps the cylinder head and block aligned before the head bolts are torqued?

A)head gasket
B)friction between head gasket and block
C)gravity
D)dowel pins

Question 13

Molded rubber gaskets should be coated with hardening-type sealer prior to installation.

Question 14

After the head has been resurfaced on an OHC engine, a stackable multilayer aftermarket head gasket can be used to restore proper cam timing.

Question 15

On some OHC engines, the camshaft[s] must be removed to adjust the valve lash.

Question 16

A torque-to-yield bolt can be reused if it is not damaged.

Question 17

Technician A coats head gaskets with black RTV. Technician B coats exhaust manifold gaskets with red RTV. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 18

What part of the head gasket is in contact with the combustion gases?

A)thermal damper
B)isomer
C)steel core
D)fire ring

Question 19

To provide a good sealing joint between the cylinder head and exhaust manifold, apply a sealant to the machined surfaces.

Question 20

A gasket adhesive does not add to the gasket's sealing ability.

Question 21

Two technicians are discussing how to repair minor scratches on the seal surface of a shaft (the part of the shaft the seal rides on). Technician A uses a mill file. Technician B uses fine emery cloth to polish the seal surface. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 22

Technician A uses adhesives to hold gaskets in place during assembly. Technician B uses RTV when an anaerobic sealant is required. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 23

Two technicians are discussing gasket installation. Technician A says if a sealant is applied to a gasket designed to be installed dry, the gasket may leak. Technician B says if a sealant is required, it will be included in the box with the gasket. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 24

Two technicians are discussing rear main seals. Technician A says modern engines use a molded synthetic rubber lip-type seal. Technician B says modern engines use a wick or rope type seal. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 25

Anaerobic sealant can be used for _____ as well as gasketing.

A)adhesive
B)vibration dampening
C)thread lubricant
D)thread locking

Question 26

Proper engine break-in procedure is being discussed. Technician A says the engine should run at idle speed for at least two hours. Technician B says the engine should be accelerated at full throttle from 30 mph to 50 mph (80 to 133 km/h). Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 27

Torque-to-yield bolts are being discussed. Technician A says compared to conventional bolts, torque-to-yield bolts offer a more consistent clamping force. Technician B says torque-to-yield bolts are tightened to a specific torque, and then rotated a certain number of degrees. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 28

Before installing a used bolt on a cylinder block, Technician A threads a new nut on the bolt to check the condition of the threads. Technician B uses a thread chaser to clean the threaded holes in the block. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 29

Graphite is a ______.

A)natural lubricant
B)synthetic lubricant
C)natural sealant
D)synthetic sealant

Question 30

Technician A measures valve lash on an OHC engine by rotating the engine to TDC for number 1 cylinder then measures the gap between the cam and tappet for all the valves. Technician B sets the engine at TDC for number 1 cylinder then measures the gap between the cam and tappet only on the valves that are closed. He then rotates the crankshaft 360 degrees and measures the gap between cam and tappet for the remaining valves. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 31

Technician A says damaged threads in a cylinder head can be repaired with a helically coiled insert. Technician B says stripped threads are commonly caused by overtorquing. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 32

Hard gaskets are made of ______.

A)steel
B)stainless steel
C)copper
D)All the answers are correct.

Question 33

The lip on a lip-type seal faces _____.

A)toward the front of the engine
B)toward the rear of the engine
C)away from the fluid it is sealing
D)toward the fluid that it is sealing

Question 34

When is a torque angle gauge used?

A)setting cam timing on a DOHC engine
B)torquing TTY head bolts
C)adjusting the timing chain tensioner
D)All the answers are correct.

Question 35

Technician A says gaskets made of paper, fiber, and cork are called soft-cut gaskets. Technician B sometimes reuses old gaskets. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 36

A bolt is considered to be ____________________ because it can be stretched and compressed up to a certain point.

Question 37

Technician A says excessive RTV on an engine gasket can cause blockage in the oil passages and cause severe engine damage. Technician B says RTV is impervious to most fluids. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 38

Technician A says aluminum expands at a different rate than cast iron. Technician B says cast iron has a coefficient of thermal expansion two or three times greater than aluminum. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 39

Technician A says some seals are designed to keep oil from escaping around a rotating shaft. Technician B says some seals are used to prevent fluid leaks between two fairly rigid flanges. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 40

What type of gasket is used on an EGR valve?

A)hard
B)soft
C)silicone RTV
D)anaerobic sealant

Question 41

RTV silicone sealing products are also known as ____________________ gasket products.

Question 42

What is a bimetal engine?

Question 43

What is meant when a bolt is stretched into yield?

Question 44

What happens when a torque-to-yield bolt is replaced with a new bolt of identical grade but torqued to the value found in a regular torque table?

Question 45

Identify the three grades and purposes of silicone gasket material.

Question 46

Describe the torque-angle method of tightening bolts.

Question 47

Name some applications of hard gaskets.

Question 48

Never use a ____________________drying sealant (such as shellac)on gaskets.

Question 49

What is the major difference between aerobic and anaerobic sealants?

Question 50

A(n)____________________ is required for a bolt that enters a water jacket.

Question 51

If a bolt is stretched into ____________________, it takes a permanent set and never returns to normal.

Question 52

Using a ____________________ is the best method of prelubricating most modern engines

Question 53

What problem does a head gasket encounter when located in a bimetal engine?

Question 54

After the combustion of the air/fuel mixture, the inner edges of the cylinder head gasket are exposed to approximately ____________________ psi (____________________ kPa)of pressure.

Question 55

Gasket material must be able to seal valve covers that are made from steel, aluminum, and ____________________.

Question 56

Identify various tasks of a cylinder head gasket.

Question 57

What are the most common causes of head gasket failure?

Question 58

Why is it important to check TSBs before replacing a failed gasket?

Question 59

A damaged bolt should be ______.

Question 60

The thermostat is installed with the temperature sensor [wax pellet] facing toward the ____________________.

Question 61

Describe how the rocker arms are adjusted on OHV engines with hydraulic lifters.

Question 62

When changing a timing belt or chain, what should you do to hold the camshaft in place?