Engine Diagnosis & Repair Flashcards
(123 cards)
1
Q
What are the 2 main types of engine blocks?
A
Cast Iron & Aluminum
2
Q
Where do you find Cylinder Liners?
A
Aluminum Blocks or Large Blocks
3
Q
What are the types of Cylinder Liners?
A
Wet & Dry
4
Q
Which Engine Block is better at conducting heat?
A
Aluminium Block
5
Q
What causes high readings on a compression test?
A
Carbon Build up
6
Q
How do you perform a Balance Test?
A
Keep Engine Idling and Disable 1 Cylinder at a time (via. scan tool or manually)
7
Q
What will a Cylinder Balance Test show you?
A
How much each cylinder is contributing & single out malfunctioning cylinder
8
Q
What is the typical compression reading on a gasoline engine?
A
150-200psi
9
Q
During a compression test, there should be no more than ___% difference between highest and lowest reading
A
20%
10
Q
What does blue/grey exhaust smoke mean?
A
Burning Oil
11
Q
What does black exhaust smoke mean?
A
Rich fuel mixture
12
Q
What does white exhaust smoke mean?
A
Coolant leakage in combustion chamber
13
Q
What causes Low Readings on a Compression Test?
A
Leaks (Vavles, Piston Rings, Head Gasket, etc.)
14
Q
What should be the proper outcome from Deglazing Piston Cylinders
A
Crosshatch Pattern with 50-60 degrees (20-60 degrees acceptable)
15
Q
What are 4 types of Cylinder wear?
A
Taper, Waviness, Scoring & out of roundness
16
Q
What is the purpose of the Crankshaft?
A
To change the reciprocating piston motion into usable rotary motion
17
Q
What is a Bearing Journal?
A
Area where bearing contact is made
18
Q
What is a Crankshaft Flange?
A
Section at the end of shaft where Flywheel attaches
19
Q
What are 2 Types of Crankshafts?
A
Cast Iron & Forged Steel
20
Q
What are 2 Types of Camshafts?
A
Cast Iron & Case Hardened Steel
21
Q
What is Valve Lift?
A
the amount that valve lobe opens the valves
22
Q
What is Lobe Lift?
A
the distance from the base circle to the cam nose (lowest point to highest point)
23
Q
How should you repair crack coming from a coolant passage on an aluminum engine block?
A
“V” out the damaged area and weld with an Aluminum Filler Rod
24
Q
What is used to pre-clean engine components prior to disassembly?
A
Spray Washers
25
What cleaning method uses high-frequency sound waves?
Ultrasonic
26
What abrasive cleaning method can be used to etch the surface of material?
Grit Media Blasting
27
What is the buildup of minerals inside the cooling system called?
Scale
28
What is usually the first step in disassembling an engine?
Remove Intake and Exhaust manifolds
29
What is the most common method for removing an engine from a FWD vehicle?
Lower the engine and transaxle as an assembly with the subframe
30
What are the 2 most common ways to measure Cam Lobe wear?
Dial Indicator & Outside Micrometer
31
What is the Block Deck?
The top surface of the block to which the cylinder head mounts too
32
Where does maximum Cylinder Bore wear occur?
Top of the Ring travel area
33
What does Piston Offset refer too?
Piston located closer to the major thrust side
34
What are most Pistons made of?
Aluminum
35
What is the purpose of Core Plugs?
Allow the release of sand from block moulding process
36
What is used to measure Cylinder Deck warpage?
Straight edge and feeler gauge
37
what is used to measure crankshaft bearing journals?
Micrometer
38
What can a Plastigage measure?
Bearing Oil clearance
39
What causes Piston Slap?
Excessive Piston clearance
40
Why are Cylinders deglazed?
to ensure proper ring sealing
41
What is another name for a connecting rod journal?
Crank Pin
42
How can a misaligned main bearing bore be corrected?
Line Boring
43
What is the correct procedure for Boring Cylinders?
bore to new piston size and hone to clearance specification
44
What type of Hone should be used during Cylinder Bore operation?
Rigid Hone
45
What measurements are taken to calculate cylinder bore taper?
Bore reading at top and bottom of ring travel at 90⁰ from block centerline
46
What speed do Balance shafts Rotate?
2x the Crankshaft speed
47
What direction do Balanceshaft rotate?
Opposite direction of the Crankshaft
48
What is the Major Thrust Side?
The side the piston contacts while moving down (power stroke)
49
What is the Minor Thrust Side?
The side the piston contacts while moving up (compression stroke)
50
What causes Cylinder Taper?
High Heat, Pressure & Lack of Lubrication
51
What causes Cylinder to be out of Round?
High Pressure & Thrust Wear (Major & Minor)
52
What causes Cylinder Waviness?
Lack of Cooling, High Heat
53
What causes Cylinder Scoring?
Debris & Lack of lubrication
54
What causes Cylinder Block Distortion?
Improper torquing of fasteners / components &
Thermal shock (Hot to Cold)
55
How do you properly store a Crankshaft or Camshaft?
Stored upright or back in the cylinder head / block
56
How are Split Bearings (insert bearing) constructed?
An upper half with an oil hole and groove and a lower half with a solid flat surface
57
Define Bearing Crush Hight
Halves are longer than the surface to provide radial pressure against the connecting rod or bearing bore to ensure good heat transfer
58
Define Bearing Spread
Bearing shell has larger arc which when installed in a bore helps to hold the shell in place during assembly
59
What is the purpose of the Harmonic Balancer?
To absorb torsional vibrations of the crankshaft
60
Which orientation does the Piston Snap Ring go?
Snap ring gap faces towards the bottom of skirt
61
What are Keeper Grooves?
Grooves at the top of the valve to keep valve in place
62
What are 2 types of Valve Seats?
Integral & Replaceable
63
What is the distance between the valve face and the valve head called?
Margin
64
What should be done to an insert style of valve seat after it is installed in the cylinder head?
Stake around the edge to secure the seat
65
Why is rocker arm ratio used on most valve trains?
To open the valves a greater distance
66
When grinding valves and seats, what is the 1 degree angle difference between them called?
Interference angle
67
Why are shims placed under valve springs?
correct valve spring installed height
68
What is the maximum deformation allowed in a cylinder head deck surface?
0.1 mm (0.004 in)
69
Which type of surfacing machine uses underside rotary cutters?
Broaching
70
What is the ideal intake valve seat width?
1.0 mm (0.040 in)
71
What is the cooling of gases by pressing them into a thin area called?
Quenching
72
What happens when valve spring tension is too low?
Valve float at high RPM
73
What is the safety factor calculated into bolt torque values?
25% below the bolt's yield point
74
What should be done to an engine block bolt hole that has been pulled up?
File, Chamfer, & Clean the bolt hole before using
75
What type of sealant would be best for sealing between machined surfaces of rigid castings?
anaerobic sealants
76
What is the correct procedure for installing the torque converter when replacing the engine?
Rotate the torque converter until it engages the transmission oil pump
77
During the initial test run, what should be done to properly break-in a rebuilt engine?
Repeat full-throttle accelerations from 50 to 80 km/h (30 to 50 mph).
78
What is the purpose of using a graphite coating on a cylinder head gasket?
to allow the head to slide across the gasket as it expands
79
What type of rear main bearing oil seal is used on current engines?
synthetic rubber lip
80
What is best method of circulating oil for initial startup of a rebuilt engine?
Use a prelubricator to prime the engine's lubrication system
81
Where does the cylinder need to be during a cylinder leak down test?
TDC on compression stroke
82
Where is the diameter if the piston measured?
Across specific points on the skirt
83
What type of core plug is used on the engine block?
Cup type core plug
84
Define Knurling
manufacturing process used to create a textured surface. Used to increase dimensions on piston skirts and valve guides
85
What is normal clearance between the piston and cylinder bore?
0.025mm - 0.050mm (0.001" - 0.002")
86
What does a steady needle mean on a vacuum test?
Engine in good condition
87
What does a steady needly, but low reading mean on a vacuum test?
Internal leakage or late timing
88
What does a fluctuating needle and low reading mean on a vacuum test?
Vacuum leak in intake system
89
What does a vibrating needle floating low to high mean on a vacuum test?
leaking head gasket
90
What does a oscillating needle and low reading mean on a vacuum test?
incorrect fuel mixture
91
What does a vibrating needle that steadies at speed mean on a vacuum test?
worn valve guides
92
What does a needle dropping regularly mean on a vacuum test?
burned valve or valve not seating
93
What does a needle dropping irregularly mean on a vacuum test?
sticking valve
94
What does a needle fluctuating when brough off idle mean on a vacuum test?
weak valve springs
95
What does a needle dropping when brought off idle mean on a vacuum test?
Retarded ignition timing
96
What does a needle rising when brought off idle mean on a vacuum test?
advanced ignition timing
97
What does a needle dropping at high RPM, then slightly rising mean on a vacuum test?
exhaust restriction
98
How do you check piston ring side clearance?
Using a feeler gauge between the piston ring and piston ring groove
99
What is the main type of valve used in automotive engines?
Poppet valve (round head with tapered face)
100
What are some advantages of a timing belt over a chain driven?
- Quieter
- Cheaper
- Lighter
- Lubrication free
101
What 4 machines are used to resurface heads?
- Belt surfacer
- Milling
- Broaching
- Grinding
102
To remove the piston and rod assemblies, what position must the crankshaft be in?
bottom of its stroke
103
What is Chamfering?
Tapping & cleaning of the threaded holes to remove the lifted surface caused by thread pulls
104
How are cast iron blocks checked for cracks?
Magnafluxing
105
How are aluminum blocks checked for cracks?
Penetrant dye & blacklight
106
What is the advantage if Integral valve seats over Insert valve seats?
Operating temperature is lower
107
What are connecting rods made of?
Steel, Cast Iron or Aluminum
108
What are the 2 types of torsional engine dampners?
Harmonic balancers & Fluid dampeners
109
How is cylinder out of round measured?
Parallel with the crank, and perpendicular to the crank
110
How do you measure piston ring side clearance?
Feeler gauge between ring and groove
111
What are the 3 types of piston pins?
Full floating, semi floating & stationary
112
What happens if valve spring tension is too low?
Valve Float
113
Where does piston thrust occur in relation to crank centerline?
90 degrees
114
What is used to prevent carbon build up on a valve face?
Valve Rotator
115
What type of threads should never be used on an Aluminum block/head?
Fine Thread
116
What helps prevent bearings from spinning in its bore?
Bearing crush
117
How do you measure openings or bores on an engine?
with a telescoping gauge
118
What effect does caustic soda have on aluminum parts?
Dissolving
119
What type of welding is used to repair cracks on an aluminum block?
TIG
120
What type of welding is used to repair cracks on an cast iron block?
Furnace Welding
121
What are the 4 types of valve lifters?
- Solid non roller
- Hydraulic non roller
- Solid roller
- Hydraulic roller
122
What is valve overlap?
both valves open slightly at the end of the exhaust stroke, and at the beginning of the intake stroke
123
What tool is used to de-glaze cylinders?
Ball hone
