Automotive Service Technician (310S) Engines Practice Exam

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