Automotive Service Technician (310S) Engines Practice Exam

These questions are part of the practice quiz. Start practicing

• How many degrees of crankshaft rotation are required to complete a four stroke cycle in one cylinder?
• Which statement best describes how direct injection differs from port injection and its effect on cold-start performance?
• Which type of piston oil ring is made of three pieces?
• Piston oil rings composed of three pieces are commonly referred to as which type?
• Which grade of silicone sealant is used in high temperature applications?
• During the four-stroke cycle, which stroke involves the intake of air-fuel mixture into the cylinder?
• Where should piston ring end gap be measured?
• What is the primary cause of coolant hose failure?
• Vacuum gauge readings determine if the piston rings are worn.
• What is the typical interference angle used in gasoline engines?
• Underside rotary cutters are used on which type of surfacing machine?
• What steps should you take when performing an oil change to ensure proper lubrication and leak prevention?
• The maximum cylinder taper normally allowed is up to how many inches?
• Which property does the viscosity of engine oil primarily describe?
• Why is following the correct torque sequence important when installing cylinder head bolts?
• What is the minimum number of valves required at the top of an engine with a four stroke cycle?
• Which statement is consistent with recommended practice for ridge removal and piston removal timing?
• In a two-stroke cycle engine, compression and intake events occur at the same time.
• Which test is used to assess a cylinder power distribution across cylinders, given normal compression and leakage tests?
• Which statement best describes the effect of a poor oil change schedule on engine cleanliness?
• How would you locate a coolant leak that shows no obvious drips, using pressure testing or dye methods?
• What is fuel trim, and how does a positive fuel trim manifest during engine operation?
• Which steps are included in a basic cooling system service procedure?
• What must be done to engine components before an effective inspection or proper machine?
• Which live data parameters are most useful to diagnose a lean condition in real time?
• Which bearing is most commonly used to support the crankshaft?
• In engines with variable valve timing, the CKP and CMP sensors provide data to coordinate which engine functions?
• What diagnostic method is commonly used to locate a vacuum leak that causes a lean condition?
• Cylinders are deglazed to ensure proper ring sealing.
• Which diagnostic step is most appropriate to isolate a misfire caused by an ignition component?
• During engine break-in, you should operate within a controlled speed range.
• The primary cause of coolant hose failure is Electrochemical degradation.
• Which symptom is commonly associated with a failing CKP sensor?
• What is compression ratio?
• Which of the following is NOT typically considered when determining service intervals for spark plugs and ignition coils on modern engines?
• In bearing geometry, the term used to describe the difference between rod bearing curvature and bore curvature is which?
• After boring a cylinder, the next step is to hone to the clearance specs.
• Pump related problems can cause low oil pressure.
• Torque specification should be followed as stated, even when bolts are lubricated.
• Valve tips can be reconditioned by grinding.
• Which statement about cylinder bore measurement is true?
• Impeller coolant pumps are most common in vehicles today.
• After ridge removal, what should be used to wipe the cylinder to prevent metal chips from spreading?
• Block heater warm-up guidance suggests it should provide which level of warming before starting the engine?
• Knurling is one of the fastest ways to restore the inside diameter dimensions of a worn valve guide.
• Which state must parts be in before they going into an abrasive blast machine
• The oil gallery is a type of core plug.
• When boring a cylinder, bore to the new piston size and hone to the clearance specs.
• How is valve lash adjustment performed?
• Which component is connected to the crankshaft and serves to store some of the engine's power?
• Piston ring end gaps should be measured at which location?
• How do downstream oxygen sensor readings affect catalytic converter monitoring and fuel control, and what issues can cause incorrect readings?
• Which valve component is typically ground to adjust seating height?
• When selecting engine oil, where should you look to determine the correct specification?
• Which parts cleaning process requires additional shot blasting or washing?
• If valve stem seals wear, what is a likely effect?
• What is the function of a knock sensor, and how does it interact with engine timing control?
• What happens if too much sealant is applied?
• Why should an oily rag be used to wipe a cylinder after ridge removal?
• How much warm up time does a block heater require?
• The valve face contact surface should be concentric with the guide to ensure seating.
• How long is the stroke of an engine compared to the length of a crankshaft throw?
• Which grade of silicone sealant is used in high temperature applications?
• In most automotive applications, what drives the water pump?
• Which symptom most likely indicates a stuck EGR valve?
• Where is the greatest amount of cylinder wear typically found?
• How would you test a faulty cooling fan or fan control module, and what would be typical failure signs?
• When diagnosing vacuum leaks, which components should be inspected for cracks or leaks?
• When diagnosing a no-start condition, what is the difference between 'no crank' and 'no run,' and what tests apply to each situation?
• During a cooling system pressure test, what would a continuous loss of pressure indicate, and what components are commonly inspected first?
• When a bolt is cleaned and lubricated how is tightening torque adjusted?
• An oil container labeled 10W-30 is given which rating when tested at -18°C?
• The typical interference angle used in gasoline engines is approximately how many degrees?
• Define compression ratio and displacement, and explain how each influences engine performance.
• Which section of the valve makes direct contact with the valve seat?
• How can live data from a scan tool assist in diagnosing engine performance problems, and what are key parameters to monitor?
• Which tool is used for precise measurement of cylinder bore diameter?
• How does radiator cap pressure affect the cooling system and what problems can arise from using an incorrect cap?
• RTV in sealant terminology stands for room-temperature vulcanizing.
• Before mounting an engine on an engine stand, which action regarding the Flex Plate or Flywheel is recommended?
• Explain the function of the ignition coil and how coil-on-plug differs from distributor-based ignition.
• Oil viscosity testing uses which temperature pair?
• What is another name for the connecting rod journal?
• What is a potential benefit of an HCCI engine?
• Dirty MAF or MAP sensors causing fuel system symptoms typically lead to which issue?
• What is the consequence of a clogged or misaligned injector spray pattern?
• Which statement best describes babbit in engine bearings?
• Which organization classifies oil by its viscosity?
• Which cleaning method uses high frequency sound waves to loosen dirt from parts?
• What is the purpose of the camshaft timing belt or chain and what wear indicators could lead to valve-to-piston interference if timing fails?
• What is babbit?
• Why is fuel rail pressure critical in direct-injection engines, and how would you diagnose rail pressure issues?
• Which operation is used to restore the inside diameter of a worn valve guide quickly?
• Why is a leak-down test performed, and how should results be interpreted?
• What is the typical maximum amount of warpage allowed on a cast iron cylinder head?
• If a dry compression test shows a low reading in a cylinder, and a wet test raises compression significantly for that cylinder, what does this indicate?
• What is the advantage of an automatic honing machine?
• How does a compression test help distinguish between mechanical problems and valve leakage as the cause of low compression?
• Distinguish between interference and non-interference engines and explain why this matters when replacing a timing belt/chain.
• What is recommended before removing the valves from a cylinder head?
• What is a typical diagnostic action to confirm a failing fuel pump beyond no-start?
• What is the primary purpose of thorough cleaning before inspection?
• What part of the valve can be ground down to restore valve stem height specifications?
• Filing the surface smooth helps seal an EGR valve when imperfections are seen on the mounting surface.
• To ensure proper seating of the valve, what is required of the valve face contact surface?
• Which procedure is used to remove a valve that is stuck in the valve guide
• Mineral scale buildup are a condition found in the cooling system.
• After installing a timing belt, what is a critical final verification step to ensure correct timing?
• Hybrid vehicles also use the motor as a generator to charge the battery.
• What is the maximum amount of cylinder taper normally allowed?
• Which check is commonly performed on valve springs?
• Graphite is a natural lubricant.
• Which component most commonly drives the water pump in a typical engine?
• What is the purpose of a wet compression test, and how can the results distinguish between ring wear and valve leakage?
• What are the four strokes of a four-stroke internal combustion engine in the correct order?
• During a cylinder leakage test, the piston must be at top dead center on the exhaust stroke in the cylinder being tested.
• The proper engine break-in procedure must be performed at which speeds?
• Which surface is primarily involved in sealing against the seat?
• Which type of coolant is not poisonous?
• Valve seats should be inspected for cracks before they are serviced.
• Filing EGR mounting imperfections is recommended.
• What is the purpose of the engine oil pressure relief valve, and what condition indicates abnormal readings?
• How can a technician correct a valve seat that is wider than specifications?
• What is the purpose of the fan shroud?
• Which observation would best indicate a misfire is caused by ignition components rather than fuel delivery?
• When must a thermostat be fully open?
• What is the purpose of performing three-angle grinding on a valve seat?
• What information do misfire counters on a scan tool provide and how can they guide repair?
• Which factor is commonly considered when determining service intervals for spark plugs and ignition coils on modern engines?
• Typically a cylinder head gasket is exposed from a vacuum to 1000 psi.
• An oversquare engine has a bigger bore than the stroke.
• Erosion of the combustion chamber would cause an aluminum cylinder head to be replaced because it costs too much to fix.
• On what is the oil filter usually mounted?
• What are the primary roles of piston rings?
• What is the function of a timing belt tensioner, and what operational symptoms indicate it may be failing?
• In a complete four-stroke cycle, how many crankshaft degrees are required to complete all four strokes?
• Which of the following is a recommended action if a valve keep grooves are damaged?
• At which temperatures is engine oil typically tested?
• The crank pin is another name for the connecting rod journal.
• What steps must be taken when replacing a timing belt on an interference engine to prevent piston-to-valve contact?
• What is the function of the engine coolant temperature (ECT) sensor, and how can a faulty sensor affect starting and fuel trims?
• Which characteristic of engine oil does viscosity measure?
• Rotor oil pump designs move the greatest volume of oil.
• Which instrument is used to measure a cylinder bore diameter?
• How does intake manifold vacuum relate to engine load and idle quality, and what conditions can cause abnormal vacuum readings?
• What is one of the primary consequences of applying an improper torque sequence or torque on head bolts?
• In which order should cylinder head bolts be removed?
• Which symptom best signals possible head gasket failure?
• Which feature causes the curvature of the connecting rod bearings to be slightly greater than the curvature of the bearing bores?
• What is a typical main bearing clearance spec?
• Which engine system removes burned gases and limits noise produced by the engine?
• Exhaust Gas Recirculation (EGR) reduces NOx emissions by what mechanism, and what are common faults that impede EGR operation?
• Why is a smoke test valuable when diagnosing vacuum leaks, and what are typical leak points?
• The coolant thermostat is most commonly located at the top of the engine block.
• Where is the most common location for the coolant thermostat?
• Which cooling system hose typically experiences the roughest service life?
• Which component stores energy to smooth engine operation and is connected to the crankshaft?
• Which condition would indicate abnormally high oil pressure in an engine?
• Describe the typical locations and purpose of the crankshaft position (CKP) sensor and the camshaft position (CMP) sensor in engines with variable valve timing.
• Why should camshaft bearing drivers not be used on aluminum heads?
• In engines with variable valve timing (VVT), what is the main performance benefit, and what maintenance issues can affect VVT operation?
• Thermal cleaning is a cleaning process that uses heat to remove contaminants from engine parts.
• Why do engines with multiple valves per cylinder tend to be more efficient than engines with two valves per cylinder?
• Silicone is an RTV sealant.
• What can occur if the cylinder ring ridge is not removed?
• What term describes the height of a valve spring when it is not installed against the retainer?
• What component helps manage the temperature of compressed air in turbocharged engines?
• In a direct-injection engine, what symptom could indicate a rail pressure issue?
• How would you diagnose a failing fuel pump, and what symptoms would you expect to observe?
• Which of the following describes the function of the crankshaft position (CKP) sensor?
• The bore is larger than the stroke in an oversquare engine.
• What is the function of the throttle position sensor (TPS), and what symptoms point to a faulty TPS?
• Which cleaning method loosens dirt from parts using microscopic bubbles created by high frequency sound waves.
• Worn valve stem seals can increase oil consumption.
• What is the purpose of spark plug heat range, and what problems can arise from using an incorrect heat range plug?
• What is the minimum number of bolts required to safely mount an engine on an engine stand?
• Why is the use of a stranded camshaft bearing driver and hammer not recommended for aluminum heads?
• What part of the piston matches the front of the connecting rod?
• To what angle are most valve seats ground?
• Insufficient oil pressure would cause the oil light to illuminate.
• Which step is essential to prevent oil leaks when performing an oil change?
• Torque values are calculated with how much safety factor below the yield point?
• Which cooling system hose is normally subjected to the roughest service life?
• Quenching describes the mixing of gases by pressing them into a thin area.
• Scale buildup of mineral and deposits are found in the cooling system.
• Which V-type engine valve train design may use four camshafts?
• Which combination of symptoms is most commonly associated with a clogged PCV valve?
• Most modern pistons are made from which material?
• Explain the function of a fuel pressure regulator in a gasoline fuel system and identify the most accurate description of its operation.
• What are typical signs of a thermostat stuck closed or stuck open, and how does each condition affect engine temperature and emissions?
• Which device is primarily responsible for adjusting fuel delivery to achieve the desired air-fuel ratio?
• Which function best describes the purpose of the exhaust system?
• Where is the engine ID tag located?
• Which sequence best describes steps to identify the faulty cylinder and root cause of a misfire?
• Before removing the pistons from the engine, the ring ridge from the top of the cylinder must be removed first.
• Valve lash adjustment state: closed.
• Which statement best describes the need for higher oil pressure and volume in turbocharged engines?
• What are the consequences of using an oil with the wrong viscosity, and how should you determine the correct specification?
• What is the purpose of the positive crankcase ventilation (PCV) system, and what are typical symptoms of a clogged PCV valve?
• Low generator output and noise can be a sign if the belts are loose.
• Piston rings wear can be indicated by vacuum gauge readings.
• What is recommended when removing a piston and rod assembly?
• Each half of a split bearing is made so it is slightly larger than exactly half. What is this extension called?
• How can a failing alternator or weak battery affect engine diagnostics and performance during tests?
• Valve seats should be inspected for cracks before they are serviced.
• An engine makes a sharp metallic rapping noise at idle that is present whether the engine is hot or cold. the noise disappears during acceleration at higher speeds, what is the most likely cause of the problem?
• Improperly installed valve spring height can cause valve spring surge or harmonics.
• If a valve has damaged keep grooves, it must be discarded.
• What is the primary function of the head gasket, and which symptoms best indicate its failure?
• How would you verify EGR valve operation using vacuum tests, and what readings would indicate a stuck or leaking EGR valve?
• In an interference engine, what is a likely consequence if timing is lost due to a worn belt or chain?
• An engine receives good results from a compression test and a cylinder leakage test but poor results from a cylinder power balance test. What could be the potential cause of the problem?
• Compare MAF and MAP sensors—what they measure, how they influence fuel metering, and the effects of dirty sensors.
• Torque values are calculated with how much safety factor below the yield point?
• How do turbocharged engines differ from naturally aspirated engines in terms of lubrication, cooling, and intake air management?
• What does DOHC stand for in engine terminology?
• Where can the engine ID tag be found?
• Where is the diameter of the piston measured?
• What is the maximum filling capacity of an anaerobic sealant?
• Excess sealant is likely to cause which of the following?
• What material are most modern pistons made from?
• What happens when a valve seat is wider than specifications?
• Margin describes the distance between the valve face and valve head.
• Explain the role of a catalytic converter and how a faulty O2 sensor can impact emissions and fuel economy.
• Oil viscosity classification is performed by which organization?