ASE A1 (Engine Repair) Practice Test - Cumulative

A only: If cylinder leakage exceeds 20%, check for air escaping the tailpipe, the PCV valve opening in the rocker arm cover, and the top of the throttle body or carburetor. Air leaking from the tailpipe usually indicates an exhaust valve leak

worn piston rings if compression increases during a wet test, this indicates worn piston rings. Compression would not increase if an exhaust valve is burned, intake valve is bent, or camshaft lobe is worn.

valve train operation: if the engine cranks properly, the battery is not the problem. Compression would not be the FIRST test, and because engine vacuum is low during a crank, a vacuum test would not be conclusive.

Both A&B Both a misfiring ignition system and an intake manifold leak could cause a cylinder to contribute too little power

B Always attempt the more simple diagnosis first

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

A&B

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

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

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

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

Neither the faulty cylinder will not cause the engine to stall, neither will it cause the engine to drop in RPM since it is faulty.

too lean idle mixture all others would not result in gauge fluctuation

listen to the customer

cracked cylinder block

loose cam bearings -loose pistons may cause a rapping noise while accel -worn cylinders may cause a rapping noise while accel -worn main bearings may cause a thumping noise when starting

start with the most difficult test

faulty carburetor -faulty ignition system, burned exhaust valve, and leaking intake manifold are likely to cause one cylinder to provide less power than others. The carburetor would not cause one single cylinder to contribute less power.

rich fuel mixture -lean fuel mixture would not cause a sulfur smell -coolant leaking into the chamber would cause a gray exhaust color -a vacuum leak would cause a rough idle that would decrease as engine speed increases

late ignition timing -burned or leaking valves cause a fluctuation between 12 and 18 -weak valve springs cause a fluctuation between 10 and 25 -leaking head gasket would cause a fluctuation between 7 and 20

tool air hose -leaking exhaust valve would cause air to escape through the tailpipe -a leaking head gasket or cracked head would cause air to escape from the radiator filler neck -worn piston rings would cause air to escape from the opening in the rocker arm cover

worn piston rings -worn intake valves would cause air leaks at the throttle body or carburetor -worn exhaust valves would cause air to leak at the tailpipe -a broken PCV valve wouldn't cause an air leak

1000 miles

disable the ignition system -ignition first, rotate (if possible), then remove spark plugs to rotate and check for coolant or oil

Both Both stuck piston rings and a plugged oil drain passage may allow oil to enter the cylinder and emit a blue/gray smoke when burned in the chamber

An ultraviolet light -All others won't cause the dye to glow

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.

Both -Stuck valves may cause bent pushrods. Improper valve timing may also cause bent pushrods.

Both -When measuring valve stem-to-guide clearance, stem diameter and guide diameter should be measured at three vertical locations (-near the top of the guide -the middle of the guide -the bottom of the guide) Either a hole or a snap gauge can be used to measure the guide diameter

B -worn valve stem seals generally do not cause stem or guide wear, but may cause excessive oil consumption

A -Valve springs must be rotated while measuring squareness. Squareness is not checked by rolling the spring on a surface plate

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.

B The piston must be at TDC on the compression stroke.

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.

A excessive cam bearing clearance may result in lower than spec oil pressure but not a clicking noise

A timing gear backlash can be measured with a dial indicator, but not with a micrometer

Both improper valve timing may cause reduced engine power and bent valves

B a stick lifter plunger may cause a burned exhaust valve, but hydraulic valve lifter bottoms should be convex.

mark the timing belt for direction none of the others are necessary

B Warpage on the cam side of the head must be measured before determining whether or not the head can be resurfaced and reused.

valve seat runout

Both

valve overheating and burning -a margin less than 1/64 inch will not cause a clicking noise. -the angle of the cut, not the margin, affects valve seating -a 1/64 margin would not cause valve seat recession

Both Removable valve seat inserts may be removed with a special puller or pry bat. Also, a special drive is used to install a new valve seat insert and the insert should be staked in place.

B Valve guide height is measured from the top of the spring seat to the top of the valve guide and excessive valve stem-to-guide clearance can result in increased oil consumption

0.125 inch 0.125 is beyond spec 0.005, 0.0625, 0.025 is within spec.

worn cam bearings -a broken timing chain, stick valve, or improper valve adjustment could cause a bent pushrod.

straightedge -plastigauge cannot effectively measure bearing alignment. -a dial indicator could not measure bearing alignment -telescoping gauge is not used to measure bearing alignment

Neither this is not a 3 angle valve job, and not poor contact (contact shown is correct).

spring seat -the cylinder head and the bottom edge of the bottom shim should not be used as a measurement location -measurement should be to the top of the spring seat, not the top shim

2 the reading should be multiplied by 2

cast-iron heads -a dye penetrant must be used on aluminum heads and aluminum intake manifolds -this type of tester is not used on pistons

by turning the adjusting nut (z)

Both -both valve spring and valve stem seal can be replaced without removing the head from the engine

Both. Lifters should be convex. If they are all cupped, the cam and lifters should be replaced

measuring timing chain stretch -cam timing is not adjusted with a ruler -TDC is not located in this manner -valve lash is not adjusted at the timing chain

0.004 inch 0.006 = V6 0.008 = V8 0.012 = V12

Both head bolts do stretch permanently when tightened and some cannot be reused

Neither -the use of unleaded fuel has nothing to do with interference angles -an interference angle will not result in a poor seal

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

a dial caliper -all others are useful tools to measure concentricity

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.

rotate the crank to position to piston #1 to TDC

Neither the cam and crank must be rotated so that the chain and sprockets can be installed with the marks pointing inward, towards each other

44.5 40 is too acute 50 is too obtuse 45.5 is too obtuse

turning the nut clockwise 2 turns at a time -this would cause the valve and piston to collide, damaging the valve train components

convex bottom -they should be convex

many older engines have torque-to-yield bolts

0.002 valve guide clearance is found dividing the measurement by 2

B valve rotators cannot be disassembled

Both

Both after valve seats are resurfaced, the valve faces should be coated with blue dye and the valves should be installed in the head. if blue dye does not transfer to the head all the way around the seat, replace the valve because it is bent or improperly ground

B the tool cannot check chamber volume

measuring tensioner length

B on OHC engines, the timing belt or chain does not have to be removed from the block before the head can be removed. In many cases, the cam sprocket is disconnected from the cam and head is lifted from the engine, leaving the belt or chain in place

B the seals are installed after the valves are installed

excessive bearing clearance excessive runout, improperly install cam bearings, and bore misalignment would cause cam binding.

A valve stems and valve guides should be lubricated with engine oil prior to assembly

A cam runout cannot be measured with the cam still mounted in the engine

runout

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

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.

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) -piston skirt & pin would not be damaged -connecting rod bearings would not be affected

A & C indicate out-of-round -A&B indicate vertical taper -C&D indicate horizontal taper -A&D do not indicate out-of-round

Both a warped head mounting surface on an engine block may cause valve seat distortion. Also, it may cause coolant and combustion leaks.

Neither. ~if the threads in a bolthole are damaged, the first step is to drill the hole over-size. the hole is then re-threaded with a tap provided with the repair kit. then, a thread repair insert (heli-coil) can be installed into the oversize hole. -- A heli-coil is not installed with a drill

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.

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.

uneven connecting rod bearing war all others are not causes of a bent connecting rod

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.

cylinder head

0.001 inch all others exceed spec

a micrometer - a pry bar may be used to bottom the crank -a dial indicator and/or feeler gauge may be used to take other measurements

A ~piston ring clearance is measured by placing a new ring in the groove and then inserting a feeler gauge between the ring and groove

both remove and install cam bearings not a tool for taking measurements

A improper balance shaft timing causes severe engine vibrations AND balance shafts are timed to the CRANK; not the cam. Some balance shafts rotate at twice the crank speed, though.

Both. it is especially important to thoroughly clean engine oil passages after bearing failure. it is also important that other parts of the lubrication system which may contain metal particles be replaced to prevent future engine damage

Neither -RTV sealant is never used on threaded fasteners -Anaerobic sealant fumes will not harm an O2 sensor

Both balance shafts should be checked for runout following the same procedure used for measuring cam runout. Balance shaft journals should be checked for taper following the same procedure used to check crank journals for taper.

replace the head if cam journal-to-bore clearance exceeds spec the cylinder head must be replaced

B ~Ring grooves should be cleaned using a ring groove cleaning tool. Also, to measure ring groove clearance, position a feeler gauge between each ring and ring groove

run a bottoming tap into the threaded galley bores -They galley bores already have tapered pipe threads

excessive thrust wear all others may require crank grinding

Neither. The bearings need to be positioned to align the oil hole in the bearing with the oil supply passage in the bore

Neither. Although balance shafts are timed to the crank, some rotate at twice the speed of the crankshaft and are also commonly found on V4 and V6 engines

B Thermal cleaners heat parts from 650-800. Also, aluminum parts can be cleaned in thermal cleaners without damage.

Both The block deck is check for warpage using a straightedge and a feeler gauge. Minor nicks or burns on the block deck can be removed using a whetstone or a file

B RTV sealant dries in the presence of air by ABSORBING moisture from the air and anaerobic sealer dries in the ABSENCE of air

Both main bearing bore out-of-round measurements of less than 0.001 inch are acceptable, so long as the vertical measurement is not the largest. the vertical measurement should never be the largest

Neither. Stretched main bearing bores cannot be corrected

rod center-to-center length

at the top of the cylinder, just BELOW the ring ridge

A warpage under 0.005 inch is usually acceptable

A ~compression rings should never be installed by spiraling them onto the piston. -the oil rings should be installed first, then the second compression ring, then the top compression ring

hammer the dished areas flat again

about 3/4 inch below the wrist pin bore centerline

taper ~crank journal taper is measured in the same direction at opposite ends

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

hub contact area scoring

Neither ~A ridge reamer should be used to remove the ridge

rod stretch ~bearings worn along the parting lines indicate rod stretch has occurred

check piston-to-cylinder wall clearance using Plastigage

Both ~if crank end play is excessive, a "clunk" noise may occur when the vehicle accelerates from a stop. Also, excessive back-and-forth motion of the crank may cause rod and main bearings to wear out permanently

the plastigage package

B ~a press-fit harmonic balancer should be removed using a special balancer remove/install tool

the same size as the original

making sure the piston in cylinder #1 is at TDC

A ~if the starter ring gear on an auto tranny flywheel is damaged, the flywheel/ring gear assembly must usually be replaced.

coolant specific gravity

a squealing noise when accelerating a SEVERELY worn or loose belt may cause a discharged battery, engine overheating, or lack of power steering assist

oxidation of the engine oil

measure the clearance between the INNER ROTOR and the housing ~ oil pump measurement should be performed with a feeler gauge: -measure pump cover flatness with a feeler gauge positioned between a straightedge and the cover -measure the clearance between the OUTER ROTOR and the housing. -measure the clearance between the inner and outer rotors with the rotors installed. -measure the clearance between the top of the rotors and a straightedge positioned across the top of the oil pump

restricted pushrod oil passages ~all other may be a cause of low engine oil pressure

engine overheating -an open in the ground circuit of the engine temp sensor will prevent the cooling fan from operating when the condenser switch is open. this may cause engine overheating -the cooling fan motor would only operate when the condenser switch is closed

damaged radiator cap vacuum valve

B the coolant boiling point rises as the pressure is increased

Both a defective water pump bearing may cause a growling noise when the engine is idling and the water pump bearing may be ruined by coolant leaking past the pump seal

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)

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

Both a noisy water pump could be caused by a corroded bearing and also by a defective seal

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

2500 RPM

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

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

Both an overtensioned v-belt can damage an alternator front bearing and can also cause the upper half of the crank front main bearing to wear permanently

hearing a groaning noise at cruising speeds -residue at the water pump drain hole may indicate a damage seal or bearings -coolant leaking from the water pump is a sign of failure -a pressure tester should indicate a water pump leak

B if the switch is stuck closed, the fan motor will continue to run because the relay receives voltage directly from the battery. also, when the a/c is turned on, the fan relay winding will be grounded through the condenser switch to activate the cooling fan

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

15 psi all others are too high

250 degrees F engine oil begins to oxidize and thicken when it reaches 250 degrees F

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

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

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

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

Both two common engine oil cooler mounting locations are: inside a radiator tank and ahead of the radiator support

a deteriorated hose inner liner -an anti-collapse spring is found in the lower, not the upper radiator hose -low coolant level will not cause this noise -contact with power steering fluid causes a hose to become soft and gummy

Both air trapped in the cooling system can cause engine overheating and a cracked cylinder head. also, on some engines, trapped air can be released by unscrewing the coolant temp sender.

A gear thickness and backlash specs are rarely provided by mfrs. the gears and housing should be inspected for scoring and other damage

B the freezing point of a coolant/water mixture starts to increase when coolant is more than 70% of the mixture

A a clogged radiator would not cause this

cut the hose off at the fitting and slit the remaining piece

away from the inside of the air filter element ~when cleaning a pleated paper-type air filter element using compressed air, hold the air gun tip about 6 inches from the inside of the filter element -air should be blown from the inside out to remove particles, and air forced into the filter are too short of a distance may damage the filter.

a manifold heat control valve stuck in the closed position reduces intake manifold temp ~the exhaust manifold on carbureted and throttle body injected engines may be equipped with a manifold heat control valve. if the manifold heat control valve is stuck open or fails to close when the engine is cold, the engine may stumble during acceleration. if the valve is stuck in the closed position, engine power will be reduced and the intake manifold will overheat.

A an intake manifold vacuum leak at idle may cause a cylinder misfire condition. an intake manifold vacuum leak will not cause a misfire condition during hard acceleration when the vacuum is lower. manifold vacuum is reduced during acceleration. Therefore, the leak would not contribute to cylinder misfire

oil accumulation in the air cleaner - a pcv valve stuck open may casue acceleration stumble -restricted pcv hose would not cause the engine to surge at high speed, nor would it lead to engine detonation

increase the clearance by 0.005. ~adding a 0.015 inch shim will increase clearance by 0.05 inch

wastegate valve stuck open all others would INCREASE boost pressure

-the mechanical advance rotates the reluctor in the opposite direction of the shaft rotation

is satisfactory

a pcv valve stuck in the open position

Neither -the mechanical advance weights rotate the cam or reluctor in the direction of distributor shaft rotation. -the vacuum advance rotates the pickup or breaker plate in a direction opposite that of distributor shaft rotation

B excessive clearance between the starter pinion gear and flywheel ring gear may cause a loud whining noise

A spark timing adjustment procedures for a vehicle can be found on an underhood label for all cars built since 1972. But, on some engines equipped with a distributor, ignition timing is not adjustable by rotating the distributor

B shims are not required for all starter but measurements should be taken to determine shim need.

according to mfrs recommendation

recharge the battery -battery should not load tested since it is discharged. the specific readings do not vary enough between cylinders to warrant battery replacement. the battery should not be refilled with fresh electrolyte; just recharged.

15 seconds

blowby gases in the air filter

Both a manifold heat control valve that is stuck closed may reduce engine power output and may cause acceleration stumble

a stuck open pcv valve

Both on an engine equipped with electronic fuel injection, a loose intake manifold may cause both engine noise and poor vehicle drivability

6 inches

Neither too much turbo boost will not cause either

B coating both sides of the rubber seals increases the likelihood that the seals will be squeezed out of place when the intake manifold bolts are tightened.

the heat riser valve on one of the exhaust manifolds is stuck shut ~a stuck shut heat riser valve will force exhaust gases through the underside of the intake manifold at all times, resulting in the manifold overheating and possibly cracking.