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ASE A1 ENGINE REPAIR MICHIGAN MECHANIC STUDY GUIDE 2024/2025 A+
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"with the engine idling, a vacuum gauge connected to the intake manifold fluctuates (from 15 to 20). These fluctuations may be caused by late ignition timing, intake manifold vacuum leaks, a restricted exhaust system,
sticky valve stems and guides, - CORRECT ANSWER sticky valve stems and guides
-late ignition timing would result in a low, steady reading -intake manifold leaks would cause a very low, steady reading -a restricted exhaust system would cause vacuum to slowly decrease after the engine was accelerated and held steady" "oil is leaking from the crankshaft rear main bearing seal on an engine. Tech A says the oil seal could be faulty. Tech B says the PCV system may not be functioning. A, B, A & B,
Neither, - CORRECT ANSWER A&B"
"A high-pitched squealing noise is heard during hard acceleration. This may be the cause of: intake manifold leak, the choke stuck closed fuel system leak
small leak in exhaust manifold - CORRECT ANSWER small leak in exhaust manifold
-intake manifold leak causes a high-pitched whistle at idle and low speeds -carb choke stuck closed will not cause a high-pitched whistle -fuel system leak normally would not cause a noise" "a heavy thumping noise occurs with the engine idling, but the oil pressure is normal. this may be caused by: worn pistons and cylinders, loose flywheel bolts, worm main bearings,
loose camshaft bearings, - CORRECT ANSWER loose flywheel bolts
-worn pistons and cylinders would cause a thumping noise during acceleration -worn main bearings cause a thump when the engine is started -loose camshaft bearings would cause a growling noise at all times" "after a vehicle is parked overnight and then started in the morning, the engine has a lifter noise that disappears after running for a short time. this may be caused by: low oil pressure, low oil level, worn lifter bottom,
excessive lifter leak-down, - CORRECT ANSWER excessive lifter leak-down
low oil pressure would result in a continuous noise low oil level would result in a continuous noise worn lifter bottom would result in a continuous noise" "when using a compression tester, the readings on the cylinders are all even, but lower than spec. this could indicate: blown head gasket, carbon buildup, cracked head,
worn rings and cylinders, - CORRECT ANSWER worn rings and cylinders
-a low reading on two adjacent cylinders may indicate a blown head gasket -carbon buildup would cause a high reading -a low reading on two adjacent cylinders may indicate a cracked head" "a cylinder balance test is being performed on an engine to determine which cylinder is causing a miss. Tech A says that when the faulty cylinder is disabled, engine rpm will drop more than for the other cylinders. Tech B says disabling the faulty cylinder will cause the engine to stall A , B, Both,
Neither, - CORRECT ANSWER Neither
"a tech has added fluorescent dye to an engine crankcase in order to locate an oil leak. The dye will glow when it is exposed to: a fluorescent light an ultraviolet light a strobe light
an infrared light - CORRECT ANSWER An ultraviolet light
-All others won't cause the dye to glow" "measurement B in the figure is more than specified. Tech A says this problem may bottom the lifter plunger. Tech B says a shim should be installed under the valve spring. A B Both
Neither - CORRECT ANSWER B only
Measure the installed valve spring height from the lower edge of the top retainer to the spring seat. Tech A is wrong. Excessive installed valve spring height will not cause the lifter plunger to bottom. Excessive installed valve spring height reduces valve spring tension, which may result in valve float and cylinder misfiring at higher speeds. Tech B is correct because is the measurement is excessive, install shims between the bottom of the valve spring and the top of the spring seat surface on the cylinder head." "Tech A says worn valve lock grooves may cause the valve locks to fly out of place with the engine running, resulting in severe engine damage. Tech B says worn valve lock grooves may cause a clicking noise with the engine idling A B Both
Neither - CORRECT ANSWER A
worn valve lock grooves may cause the valve locks to fly out of place with the engine running, resulting in severe engine damage, but will not cause a clicking noise." "While adjusting mechanical valve lifters, Tech A says when the valve clearance is checked on a cylinder, the piston in that cylinder should at TDC on the exhaust stroke.
Tech B says some mechanical valve lifters have removable shim pads available in various thicknesses to provide the proper valve clearance A B Both
Neither - CORRECT ANSWER B
The piston must be at TDC on the compression stroke." "the tool in the figure is being used to check the: valve lifter height camshaft journal out-of-round pushrod length
camshaft lobe lift - CORRECT ANSWER camshaft lobe lift
valve lifter height and pushrod length would not be measured in this manner. cam journal out-of- round should be measured with a micrometer." "when discussing camshaft bearing clearance, Tech A says excessive camshaft bearing clearance may result in lower-than-spec oil pressure. Tech B says excessive cam bearing clearance may cause a clicking noise when the engine is idling A B Both
Neither - CORRECT ANSWER A
excessive cam bearing clearance may result in lower than spec oil pressure but not a clicking noise" "on engines where where the cam drive gear teeth mesh directly with the crank gear teeth, Tech A says the timing gear backlash may be measured with a dial indicator. Tech B says on this type of engine, the timing gear backlash may be measured with a micrometer A B Both
Neither - CORRECT ANSWER A
timing gear backlash can be measured with a dial indicator, but not with a micrometer"
0.125 is beyond spec 0.005, 0.0625, 0.025 is within spec." "all of the following could cause a bent pushrod except: worn cam bearings broken timing chain sticking valve
improper valve adjustment - CORRECT ANSWER worn cam bearings
-a broken timing chain, stick valve, or improper valve adjustment could cause a bent pushrod." "on an OHC engine with removable bearing caps, which of the following is used to measure bearing alignment straightedge plastigauge dial indicator
telescoping gauge - CORRECT ANSWER straightedge
-plastigauge cannot effectively measure bearing alignment. -a dial indicator could not measure bearing alignment -telescoping gauge is not used to measure bearing alignment" "In the figuure, Tech A says that a three-angle valve job is shown. Tech B says that poor valve face to valve seat orientation is shown. A B Both
Neither - CORRECT ANSWER Neither
this is not a 3 angle valve job, and not poor contact (contact shown is correct)." "tech A says that if a vehicle uses unleaded gasoline, an interference angle must be used on the valves. tech B says an interference angle creates a poor seal when the engine is first starter after reconditioning valves
A
B
Both
Neither - CORRECT ANSWER Neither
-the use of unleaded fuel has nothing to do with interference angles -an interference angle will not result in a poor seal" "the rocker arms on a pushrod engine have 1:5:1 ration. this means that: a cam lift of 0.250 will cause the valve to open 0.188 inch a cam lift of 0.250 will cause the valve to open 0.375 inch the engine must be fitted with hydraulic lifters
the engine must be fitted with roller lifters - CORRECT ANSWER a cam lift will cause the
valve to open 0.375 inch (0.250 x 1.5) the rocker arm ratio does not determine which type of lifters must be used" "valve face and seat concentricity can be measured with all of the following EXCEPT a concentricity tester a dial caliper blue dye
a dial indicator - CORRECT ANSWER a dial caliper
-all others are useful tools to measure concentricity" "tech A says that valve lock grooves on the valve stems must be inspected for rounded shoulders. tech B says valve stems having rounded or uneven shoulders require machining A B Both
Neither - CORRECT ANSWER A only
valve lock grooves on the valve stems must be inspected for rounded shoulders. Also, rounded or uneven shoulders should be replaced, not machined."
A
B
Both
Neither - CORRECT ANSWER B
the seals are installed after the valves are installed" "the LEAST LIKELY cause of cam bind would be excessive runout improperly installed cam bearing bore misalignment
excessive bearing clearance - CORRECT ANSWER excessive bearing clearance
excessive runout, improperly install cam bearings, and bore misalignment would cause cam binding." "tech A says that carelessly installed valve stem seals may cause excessive oil consumption. tech B says that valve stem seals should be lubricated with grease before the valves are installed A B Both
Neither - CORRECT ANSWER A
valve stems and valve guides should be lubricated with engine oil prior to assembly" "tech A says that cam lobe lift can be checked with the cam still mounted in the engine. tech B says the cam runout can be checked with the cam still mounted in the engine A B Both
Neither - CORRECT ANSWER A
cam runout cannot be measured with the cam still mounted in the engine" "the measuring tool in the figure is checking the cam journal condition runout
lift
bearing clearance - CORRECT ANSWER runout"
"which of the following steps is the tech LEAST LIKELY to take when pressing the wrist pin into the piston and connecting rod -align the bores in the piston and connecting rod -heat the small end of the rod -make sure that position marks on the piston and connecting rod are oriented properly
-heat the wrist pin - CORRECT ANSWER heat the wrist pin
(heating the wrist pin is the LEAST LIKELY step because it will cause the pin to expand and prevent it from fitting into the connecting rod and piston bores) -the bores in the piston and the rod should be aligned before pressing in the wrist pin -the small end of the rod should be heated before pressing in the wrist pin -position marks on the piston and rod should be oriented properly before pressing in the wrist pin" "tech A says a special puller and installer tool is required to remove and install the vibration damper. tech B says if the inertia ring on the vibration damper is loose, the damper must be replaced A B Both
Neither - CORRECT ANSWER Both
A special puller and installer tool are required to remove and install the vibration damper. Using a regular gear puller to remove the vibration damper will damage the damper. Also, a loose inertia ring on the damper requires replacement of the damper." "if new rings are installed without removing the ring ridge, what may be the result? -piston skirt may be damaged -piston pin may be broken -connecting rod bearings may be damaged
-piston ring lands and/or top compression ring may crack - CORRECT ANSWER piston ring
lands and/or top compression ring may crack (failing to remove the ridge ring may cause piston ring lands and/or the top compression ring to crack or break after the engine is assembled and started)
200-300 degrees 550-700 degrees 700-900 degrees
650-800 degrees - CORRECT ANSWER 650-800 degrees
~this temp will cause the contaminants to oxidize. after the thermal cleaning process, the ash is removed by shot blasting or washing the parts." "tech A says metal burrs on the crank flange may cause excessive wear on the ring gear and starter drive gear teeth. tech B says metal burrs on the crank flange may cause improper torque converter-to- transmission alignment. A B Both
Neither - CORRECT ANSWER Both
~Burrs on the crankshaft flange might prevent the flywheel or flexplate from seating properly. During engine operation, this will cause the flywheel or flexplate to wobble, damaging the flywheel and starter gear teeth (during cranking) and the transmission torque converter bushing." "a bent connecting rod may cause uneven connecting rod bearing wear uneven main bearing wear uneven piston pin wear
excessive cam bearing wear - CORRECT ANSWER uneven connecting rod bearing war
all others are not causes of a bent connecting rod" "tech A says the timing cover must be removed in order to replace the crank front oil seal. tech B says the lip on the front oil seal must face toward the crank pulley or harmonic balancer A B Both
Neither - CORRECT ANSWER Neither
~on some engines, the crank front oil seal can be replaced without removing the timing cover. Also, lip type seals are installed with the lip of the seal facing the fluid being sealed."
"the LEAST likely place an RTV sealer would be used is the: oil pan valve cover intake manifold
cylinder head - CORRECT ANSWER cylinder head"
"when measuring main bearing bores, provided the vertical reading is not largest, out-of-round measurements are acceptable if less than: 0.001 inch 0.010 inch 0.005 inch
0.015 inch - CORRECT ANSWER 0.001 inch
all others exceed spec" "a crank journal is being measured in the same direction at opposite ends. this is measuring for: taper out-of-roundness wear
bearing size - CORRECT ANSWER taper
~crank journal taper is measured in the same direction at opposite ends" "A says that flywheel runout is checked using a dial indicator while the flywheel is still mounted on the crankshaft. B says that flywheel runout is checked using a dial indicator and stand after removing the flywheel from the engine and placing it on a surface plate A B Both
Neither - CORRECT ANSWER A
~flywheel runout should be checked with the flywheel mounted on the crank and the dial indicator mounted on the block or clutch so that it contacts the flywheel wear surface" "vibration damper rubber should be inspected for all of the following EXCEPT: hub contact area scoring
A
B
Both
Neither - CORRECT ANSWER A
many thermostats are marked to indicate which way the coolant should flow through them. also the thermostat should be installed so that the thermal element points toward the ENGINE (not the radiator)" "A says that a soft or gummy heater hose may be caused by a missing exhaust manifold heat shield. B says that a brittle or hard lower radiator hose may be caused by engine oil leaking onto the hose A B Both
Neither - CORRECT ANSWER Neither
-excessive heat will cause a heater hose to become hard and brittle -engine oil will cause a radiator hose to become soft and gummy" "A says that a noisy water pump could be caused by a corroded bearing. B says that this could be cause by a defective seal A B Both
Neither - CORRECT ANSWER Both
a noisy water pump could be caused by a corroded bearing and also by a defective seal" "an electric cooling fan is inoperative. A says that this could be caused by a bad ground in the cooling fan circuit. B says this could be caused by a bad wire to the fan relay A B Both
Neither - CORRECT ANSWER Both
an inoperative electric cooling fan could be caused by a bad ground in the cooling fan circuit and also by a bad wire to the fan relay" "with the engine at normal operating temperature, the oil pressure test is usually performed at idle speed and a higher speed such as: 1,500 RPM 2,000 RPM 2,500 RPM
3,000 RPM - CORRECT ANSWER 2500 RPM"
"A says that replacing a 180 degrees F thermostat with a 195 degrees F thermostat will cause the engine to warm up faster. B says that removing the thermostat from an engine may cause "hot spots" to develop in the engine A B Both
Neither - CORRECT ANSWER B
installing a higher rated thermostat will not cause the engine to warm up faster but will only cause the engine to operate at a higher temp" "if either the radiator pressure cap sealing gasket or the radiator filler neck seat are damaged, which of the following is LEAST likely to occur? the lower radiator hose will burst the engine coolant will boil the engine coolant will overflow
the engine will overheat - CORRECT ANSWER the lower radiator hose will burst
-coolant may boil due to low pressure in the system -coolant may overflow through the damaged seal or gasket -if the pressure gets too low or enough coolant is lost, the engine may overheat" "A says that an overtensioned V-belt can damage the alternator front bearing. B says an overtensioned V-belt can cause the upper half of the crank front main bearing to wear prematurely A
Neither - CORRECT ANSWER Both
some engines are fitted with a type of oil pump that fits over the crank snout. others, especially ohc belt-timed engines, have a belt-driven pump" "as shown, a tester pump is being used to pressure test the engine cooling system. How much pressure should be applied to the cooling system when operating a tester pump? 15 psi 17.5 psi 20 psi
22.5 psi - CORRECT ANSWER 15 psi
all others are too high" "on turbocharged engines, the lubricating oil is frequently routed through an external oil cooler. the cooler prevents the oil from getting hot enough to oxide and thicken, a process that begins when oil reaches a temp of: 100 degrees F 150 degrees F 200 degrees F
250 degrees F - CORRECT ANSWER 250 degrees F
engine oil begins to oxidize and thicken when it reaches 250 degrees F" "the oil light on a vehicle stays on while the engine is running. A says this could be caused by too much cam bearing clearance. B says a grounded wire in the oil lamp warning lamp circuit could cause this A B Both
Neither - CORRECT ANSWER Both
excessive cam bearing clearance or a grounded warning indicator circuit could cause the oil pressure light to remain on while the engine is running" "a vehicle is equipped with a coolant recovery system. coolant does not return to the radiator when the engine cools. A says that the transfer hose may be plugged. B says that the filler neck soldered joint could be cracked
A
B
Both
Neither - CORRECT ANSWER both
both a plugged transfer hose and a cracked filler neck soldered joint could prevent coolant from returning to the radiator when the engine cools" "a thermostat-testing setup is shown in the figure. A says the thermostat will start to open when the water boils. B says the thermostat valve should be fully open when the temp equals the rated temp stamped on the thermostat A B Both
Neither - CORRECT ANSWER Neither
-the thermostat should be fully open long before the water starts to boil -the thermostat should start to open when the water temperature reaches its rated temperature" "serpentine belt stretch is indicated by: using a belt tension gauge belt deflection a squealing noise at idle
using the scale on the tensioner housing - CORRECT ANSWER using the scale on the
tensioner housing -a belt tensioner gauge is used to check tension on standard v-belts -measuring belt deflection on a v-ribbed belt is not the best method -a squealing noise at idle would indicate a loose or worn belt" "A says that an engine oil cooler can be located inside one of the radiator tanks. B says that an engine oil cooler can be mounted ahead of the radiator support A B Both
