AUT-122 Final exam
To complete a four-stroke cycle in one cylinder, the crankshaft must rotate _____ degrees.
720
water pump failure can be caused by a bent fan blade
true
The stroke of an engine is _____ that of a crankshaft throw
twice
A wet compression test is performed on an engine after a dry compression test revealed low compression on one cylinder. If the compression on the low cylinder rises, it indicates _____.
worn rings
For every 1 pound of pressure put on engine coolant, the boiling point of the coolant is raised about _____ degrees Fahrenheit degrees (_____ degrees Celsius).
3, 1.7
The shop manual should have a picture of the head bolt tightening sequence. If there is no shop manual or technical data available, the best tightening sequence would be:
A circular pattern beginning in the center and ending on the outboard ends
Which operation must be performed before removing the pistons from an engine?
Install rod bolt protector sleeves, Remove the cylinder ridge with a ridge reamer, and If the connecting rods are not marked from the factory, number the rods with a prick punch or number stamp
What should be done to correct bolt holes in the block that are pulled up [raised]?
The bolt holes should be tapered at the surface by chamfering
Technician A says a piston pin is sometimes called a wrist pin. Technician B says the piston pin is always centered in the piston. Who is correct?
a only
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 only
Technician A says heat is transferred from an exhaust valve to the cylinder head through the valve seat. Technician B says some exhaust valves have a hollow stem filled with silicone to transfer heat to the valve guide. Who is correct?
a only
Technician A says the engine displacement can be found on the engine ID tag. Technician B says the date the engine was assembled can be found in the casting numbers on the cylinder block. Who is correct?
a only
Cylinder head warpage can be measured with _____.
a straightedge and feeler gauge
When lubrication of a fastener is recommended prior to installation, ______.
apply lubricant to bolt threads
citrus chemicals _____
are easier to dispose of
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 133km/h). Who is correct?
b only
Technician A says cooling system pressure is regulated by the pressure relief valve in the water pump. Technician B says cooling system pressure is regulated by the radiator cap. Who is correct?
b only
Technician A says the end of the valve spring that is wound the tightest should face toward the spring retainer. Technician B says the O-ring seal should be installed in the lowest of the keeper grooves on the valve stem.
b only
To ensure proper seating of the valve, the valve seat must _____.
be the correct width, have the correct location on the valve face, and be concentric with the guide
Technician A says VVT [variable valve timing] engines use a cam phaser that advances or retards the camshaft as theengine is running. Technician B says VVT engines use a third cam lobe with increased lift and duration, operating a thirdrocker arm that is coupled to the two primary rocker arms by a hydraulically controlled pin, while the engine is running.Who is correct?
both a and b
Technician A says a dry sump lubrication system eliminates the possibility of oil sloshing and possible oil starvation during hard cornering, braking, and acceleration. Technician B says a dry sump lubrication system allows the engine to be mounted lower in the frame, improving handling. Who is correct?
both a and b
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?
both a and b
Technician A says excessive buildup of sludge may indicate a poor oil change schedule. Technician B says a build up of scale in the engine can cause cooling system blockage. Who is correct?
both a and b
Technician A says gaskets made of paper, fiber, and cork are called soft cut gaskets. Technician B always uses new gaskets and never reuses old ones. Who is correct?
both a and b
Technician A says it is a good practice to clean the engine and engine compartment before beginning to remove the engine. Technician B says all engine fluids should be drained before engine removal. Who is correct?
both a and b
Technician A says multivalve engines can have three valves per cylinder. Technician B says multivalve engines can have five valves per cylinder. Who is correct?
both a and b
Technician A says positive valve stem seals fit tightly around the top of the stem. Technician B says positive stem seals scrape oil off the valve as it moves up and down. Who is correct?
both a and b
Technician A says that the oil pump is driven directly by the crankshaft. Technician B says on some older engines the oil pump is driven by the distributor. Who is correct?
both a and b
Technician A says the distance across the outside parting surface of the bearing is slightly greater than the diameter of the housing bore, and this feature is called spread. Technician B says when a connecting bearing half is installed, the bearing edges extend slightly from the seat; this extension is called bearing crush. Who is correct?
both a and b
Technician A uses a chalk mark to index the position of the rear U-joint and pinion flange. Technician B, when removing drive axles, scribes marks on the suspension and steering parts to ensure that the wheel alignment will be close after reassembly. Who is correct?
both a and b
Two technicians are discussing a vehicle with an overheating problem. There are no leaks, internal or external. The belts are in good condition, and the radiator has been removed and flow tested. Everything appears to be in good condition. A new thermostat was installed, but it did not cure the problem. Technician A says the impeller could be slipping on the water pump shaft. Technician B says the impeller blades could be corroded. Who is correct?
both a and b
Two technicians are discussing gasket installation. Technician A says if sealant is applied to a gasket designed to be installed dry, the gasket may leak. Technician B says if sealant is required, it will be included in the box with the gasket. Who is correct?
both a and b
Two technicians are discussing oil filters. Technician A says the oil filter has an anti-drain-back valve that prevents the oil in the filter and engine oil passages from returning to the sump when the engine is shut down. Technician B says the oil filter has a bypass valve that in the event the filter becomes plugged, oil can flow directly to the bearings. Who is correct?
both a and b
Two technicians are discussing undersized bearings. Technician A says a 0.001 in. or 0.002 in. bearing can be used ona stock crankshaft journal if the oil clearance [difference between the bearing diameter and the journal diameter] isslightly excessive and the journal is not excessively tapered or out of round. Technician B says 0.010 in., 0.020 in., and0.030 in. undersized bearings are only used when the crankshaft journals have been reground. Who is correct?
both a and b
All the following are types of oil pumps except _____.
centrifugal
Which of the following solvents have associated health risks?
chlorinated hydrocarbons, mineral spirits, and caustic soda
Valve springs should be checked for all of the following EXCEPT:
compressed height
Babbitt, a mixture of lead and tin, is used in _____.
connecting rod and main bearings
The reciprocating movement of the piston is converted into rotary motion by the _____.
crankshaft and connecting rod
Oil coolers are normally found on _____ vehicles.
diesel, high performance and turbocharged vehicles
To drain a cooling system that does not have a petcock or drain plug in the radiator, ______.
disconnect lower radiator hose
A pressure relief (regulator) valve, located inside the oil filter, is designed to limit engine oil pressure.
false
All head bolts in an engine are the same length.
false
Molded rubber gaskets should be coated with hardening-type sealer prior to installation.
false
Tightening of a bolt should be done with an impact wrench followed by a torque wrench.
false
If the fan shroud is removed from a vehicle, _____.
the engine will overheat during prolonged idling
When is a torque angle gauge used?
torqueing TTY head bolts
Elasticity means that a bolt can be stretched or compressed.
true
Normally 30 to 50 percent of the engine's coolant remains in the system after the radiator has been drained
true
Stainless steel is nonmagnetic.
true