ASE A1 (Engine Repair) Practice Test – Cumulative ALL SOLUTION LATEST EDITION 2025 GUARANTEED GRADE A+

ASE A1 (Engine Repair) Practice Test – Cumulative ALL SOLUTION LATEST EDITION 2025 GUARANTEED GRADE A+ an engine miss is being diagnosed using a cylinder leakage test. Technician A says that any cylinder with over 20% leakage has excessive leakage. Tech B says that air leaking from the tailpipe indicates a cracked cylinder. A only, B only, A & B, Neither . 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 during a compression test, a cylinder has 40% of the specified compression reading. When the tech performs a wet test, the compression reading on this cylinder has 75% of the specified reading. The cause of the low compression reading could be worn piston rings, a burned exhaust valve, a bent intake valve, a worn camshaft lobe, 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. the customer complains that the engine cranks but does not start; the first thing to check should be valve train operation, battery voltage, compression, engine vacuum, 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. during a cylinder balance test on an engine with fuel injection, one cylinder provides very little rpm drop. Tech A says the ignition system may be misfiring on that cylinder. Tech B says the engine may have an intake manifold vacuum leak. A only, B only, A & B, Neither , Both A&B Both a misfiring ignition system and an intake manifold leak could cause a cylinder to contribute too little power while discussing basic diagnostic procedures, Tech A says the most complicated diagnostic tests should be performed first. Tech B says that you should first question the customer to obtain as much info as possible about the problem A, B , A & B, Neither, B Always attempt the more simple diagnosis first 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, 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, 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 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, 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, 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, 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, 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. an engine is idling at 750 rpm. the pointer on the vacuum gauge is floating between 11 and 16 in Hg. The most likely cause is retarded timing, advanced timing, stuch EGR valve, too lean idle mixture, too lean idle mixture all others would not result in gauge fluctuation the first step a Tech should take for diagnosis is: think of possible causes of the problem, question the customer, road test the vehicle, listen to the customer, listen to the customer the customer says that the engine requires excessive cranking to start. the LEAST likely cause of this problem would be: cracked cylinder block, jumped timing belt, faulty fuel pump, stuck-open EGR valve, cracked cylinder block which of the following is LEAST likely to cause engine noise? loose pistons, worn cylinders, worn main bearings, loose camshaft bearings, 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 the least likely first step in a diagnosis would be to: question the customer for more info, be sure that the customer complaint is eliminated start with the most difficult test road test the vehicle start with the most difficult test a cylinder balance test on a carbureted engine has revealed one cylinder is contributing less power than the others. The LEAST likely cause of this is: faulty ignition system burned exhaust valve faulty carburetor leaking intake manifold 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. an excessive sulfur smell in the exhaust with a cat can be an indication of: lean fuel mixture coolant leaking into combustion chamber rich fuel mixture vacuum leak 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 a low, steady vacuum gauge reading from 11 to 15 indicates: burned or leaking valves late ignition timing weak valve springs leaking head gasket 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 during a cylinder leakage test using a cylinder leakage tester, the reading exceeds 20%. The least likely place the tech would for leaking air would be: tool air hose vehicle tailpipe radiator filter neck PCV valve opening in the rocker arm cover 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 during a cylinder leakage test, air comes out of the PCV valve opening in the rocker arm cover. This is an indication of: worn intake valves worn exhaust valves a broken PCV valve worn piston rings 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 even a small oil leak can result in major oil loss. It has been estimated that three drops of oil leaking every 100 feet results in a total of 3 quarts (2.8 liters) of oil loss every 100 miles 500 miles 1500 miles 1000 miles 1000 miles if the starter motor does not crank the engine, the first diagnostic step a tech should take is: disable the ignition system remove the spark plugs rotate the engine by hand watch for oil or coolant flow from spark plug holes disable the ignition system -ignition first, rotate (if possible), then remove spark plugs to rotate and check for coolant or oil Tech A says blue-gray smoke coming from the exhaust may be caused by stuck piston rings. Tech B says this could be caused by a plugged oil drain passage in the cylinder head... A B Both Neither 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 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 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 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 that stuck valves may cause bent pushrods. Tech B says that improper valve timing may cause bent pushrods A B Both Neither Both -Stuck valves may cause bent pushrods. Improper valve timing may also cause bent pushrods. when measuring valve stem-to-guide clearance, Tech A says the valve stems and guides should be measure at 3 vertical locations. Tech B says the valve guide diameter should be measured with either a hole or snap gauge A B Both Neither 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 Tech A says worn valve stem seals may cause rapid valve stem and guide wear. Tech B says worn valve stem seals may cause excessive oil consumption A B Both Neither B -worn valve stem seals generally do not cause stem or guide wear, but may cause excessive oil consumption While measuring valve springs, Tech A says the valve spring must be rotated while measuring squareness. Tech B says that spring squareness can be checked by rolling the spring on a surface plate A B Both Neither A -Valve springs must be rotated while measuring squareness. Squareness is not checked by rolling the spring on a surface plate 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 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 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 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 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 A timing gear backlash can be measured with a dial indicator, but not with a micrometer Tech A says improper valve timing may cause reduced engine power. Tech B says improper valve timing may cause bent valves in some engines A B Both Neither Both improper valve timing may cause reduced engine power and bent valves Tech A says hydraulic valve lifter bottoms should be flat or concave. Tech B says a sticking lifter plunger may cause a burned exhaust valve A B Both Neither B a stick lifter plunger may cause a burned exhaust valve, but hydraulic valve lifter bottoms should be convex. when removing the timing belt from an OHC engine, the tech must first: remove the rocker arm assembly mark the timing belt for position mark the timing belt for direction remove the water pump mark the timing belt for direction none of the others are necessary an OHC cylinder head is being inspected and the feeler gauge is 0.014 inch thick. Tech A says the head should be resurfaced and reinstalled. Tech B says the warpage on the cam side must be measured to determine if the head is usable A B Both Neither B Warpage on the cam side of the head must be measured before determining whether or not the head can be resurfaced and reused. in the figure, the technician is most likely checking: valve guide depth valve seat angle cylinder head flatness valve seat runout valve seat runout while discussing torque-to-yield head bolts, Tech A says compared to conventional head bolts, torque-to-yield bolts provide a more uniform clamping force. Tech B says torque-to-yield bolts are tightened to a specific torque-to-yield bolts are tightened to a specific torque and then rotated tight a certain number of degrees. A B Both Neither Both a valve margin of 1/64 inch may cause a clicking noise at idle valve overheating and burning improper valve seating valve seat recession 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 Tech A says removable valve seat inserts may be removed with a special puller or a pry bar. Tech B says a special driver is used to install the valve seat insert, and the insert should be staked after installation A B Both Neither 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. Tech A says valve guide height is measured from the bottom of the valve guide to the top of the valve guide. Tech B says increased oil consumption may result from excessive valve stem-to-guide clearance A B Both Neither 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 A bent valve spring must be replaced if it has a spring height variance of more than 0.005 inch 0.0625 inch 0.125 inch 0.025 inch 0.125 inch 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 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 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 Neither this is not a 3 angle valve job, and not poor contact (contact shown is correct). valve spring installed height is measured between the lower edge of the top retainer and the: cylinder head top edge of the top shim bottom edge of the bottom shim spring seat 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 the tech is using a torque wrench operated valve spring tester to measure valve spring tension. the tech pulls on the torque wrench until a click or ping is heard. the reading at this point needs to be multiplied by: 2 3 4 5 2 the reading should be multiplied by 2 an electromagnetic-type tester and iron fillings may be used to check for cracks in: aluminum heads pistons cast-iron heads aluminum intake manifolds 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 in the figure, how is valve lash adjusted? adding shims to point w adding shims to point x no adjustment is required by turning nut z by turning the adjusting nut (z) CONTINUED...