Engine coolant contaminated by engine oil on a compression ignition engine would be caused by:, Internal leakage of the oil cooler, Worn piston compression rings, Worn piston oil control rings, Cankshaft, The fuel pressure in a common rail fuel system can be checked by:, Connect pressure gauge to fuel return line and run engine, Connect pressure gauge to injector pipe and run engine, Connect pressure gauge to rail and run engine, Connect pressure gauge to inlet side of the fuel pump, The function of the condenser in an air conditioning system is to:, Isolate the compressor from damaging liquid refrigerant, Separate gas and liquid, Radiate heat, Regulate refrigerant flow to the evaporator, The operating voltage of a throttle pedal with electronic engine management is typically:, 0.5v to 4.5v, 12v to 24v, 9v to 18v, 0v to battery voltage, A typical variable valve timing system:, Increases duration of valve opening as engine speed reduces, Reduces inlet valve opening as engine speed increases, Reduces duration of valve opening as engine sped increases, Increase duration of valve opening as engine speed increases, After replacing injectors in an electronic fuel injection system. Vehicle should be checked by:, Carry out smoke test in line with MOT requirements for car, Carry out full road test, check for leaks and fault codes, Hold engine at maximum speeds for 30 seconds, Person who drives car check for difference in performance, The main function of exhaust gas recirculation is to:, Recycle exhaust gas to reduce combustion temperature, Recycle exhaust gas to improve fuel economy, Re-burn exhaust gas to reduce carbon dioxide, Re-burn exhaust gas to reduce carbon monoxide, When comparing a multi-point fuel injector against single point injection:, Multi-point system, requires a larger fuel tank, Single point delivers more accurate quantities of fuel, More accurate ignition timing of the injector is required, The sequential system delivers better fuel economy , Waste gate valve has seized closed on a turbo. What effect will it have on boost pressure?, Turbo will over boost at low engine revs, Turbo will under boost when engine under heavy load , Turbo will under boost and increase turbo lag, Turbo will over boost when engine under heavy load, Which test on an engine crankshaft requires the use of vee blocks and a dial test indicator?, Checking for bow, Checking for twist, Checking for taper, Checking for big and ovality, An inductive type sensor signals engine speed to the engine control unit by:, Producing data bus packets that vary in size with speed, Producing AC voltage that varies frequency with engine speed, Producing PWM signal that varies in length with engine speed, Producing DC voltage that varies frequency with engine speed, On what date were EURO 5 emission standards introduced on passenger vehicles?, 1st April 2004, 1st October 2005, 1st October 2009, 1st April 2003, Pinking occurs when:, Flame front travels too slowly across combustion chamber, Flame front travels too quickly across combustion chamber, Engine is running below normal operating temperature, Ignition timings are set to an advanced position, Which component requires removal to carry out cylinder leakage test on a spark ignition engine?, Spark plug, Inlet manifold, Exhaust manifold, Cylinder head, The advantage of a multipoint injection system over a carburettor petrol system is that:, There is a better atomisation of the fuel, It delivers better fuel economy , All the answers given, The quantity of fuel delivered is tightly controlled, On a car heater system. A customer complains of loss of power on slower speeds. What's the fault?, Coolant sensor faulty, Motor brush faulty, Resistor pack failure, Faulty switch unit, Low compression on 1 cylinder on SI engine carry out wet test, result is still the same. Possible cause is:, Burnt valve seats , Worn piston , Slows ignition timing, Worn big end bearings, Where on a vehicle would you expect to find an oxygen sensor, Part of closed loop system, in exhaust before cat, Part of closed loop in inlet manifold, Part of open loop in inlet manifold, Part of open loop in exhaust before cat, Engine losing coolant through expansion pipe due to excessive pressure. Possible cause could be, Blocked air filter, Coolant is contaminated with oil, Coolant antifreeze beyond service life, Internal leakage from cylinder head gasket, A fuel's flash point is the:, Anti-knock index number of a fuel, Measure of how quickly it vaporises at ambient temperature, Temperature at which fuel will automatically ignite in air, Temperature fuel will vaporise forming ignitable mixture, Excessive valve clearances in a spark ignition engine will cause:, The valve overlap to be increased, The valve timing to be advanced, The valve timing to be decreased, The point of ignition to be advanced, What type of output signal do most hall type sensors produce when tested with an oscilloscope?, Cosine wave, Square wave, Variable Capacitance, Sine Wave, A common rail injector is triggered by a PWM signal the longer the pulse width:, The lower the injector resistance, The higher the injector resistance, The more fuel is injected, The less fuel is injected, Condition of turbo charger bearings can be assessed by:, Measuring the maximum boost pressure, Measure the turbine to housing clearance using feeler blades, Measure turbine shaft end float using a DTI gauge, Lifting the turbine shaft by hand, An intercooler is used to:, Cool the exhaust gas to decrease NOx content, Cool the exhaust gas to increase NOx content, Cool the inlet air to decrease its density, Cool the inlet air to increase its density, Air mass meters calculate the mass of air entering the engine by: , Measuring current req to keep wire or film at constant temp, Measure ambient and air temp in the inlet manifold, Measure piston speed and air emp in intake manifold, Measure air speed and volume in the intake manifold, An engine which produces above atmospheric pressure in the inlet manifold:, Is a two stroke engine design, Has variable valve timing, Has a pressure-charger fitted, Has a high compression ratio, In the combustion cycle of a CI (diesel) engine the 'delay period' is the:, Crank angle injected fuel burns rapidly reducing heat energy, Crank angle when injectors spray fuel in combustion chamber, Time that the air in cylinder compressed by rising piston, Time before self-ignition when injected fuel absorbs heat, What is meant by the word flash point when talking about fuel?, The highest temperature at which it will combust, The average temperature at which it will combust, The range of temperature at which it will combust, The lowest temperature at which it will combust, An inductive type engine speed sensor produces, A PWM signal which varies in length with engine speed, Data bus packets which vary in size with engine speed, A DC voltage which varies in frequency with engine speed. , An AC voltage which varies in frequency with engine speed, The communication network system shown in the diagram is called a:, Main controller system, Multi ECU system, Pulse width modulation system, Multiplex system, Blow by gasses in the crankcase are removed by the, PCV system, Evaporation control system, Catalytic convertor, EGR system, A common rail engine will crank but not start. No codes are present in the ECU, Faulty manifold pressure sensor, Faulty coolant temperature sensor , Blocked fuel filter, Faulty knock sensor, A common rail engine will start and idle but has a constant misfire. One fault could be:, Faulty spark plug, Faulty airflow sensor, Faulty coolant temperature, Faulty injector wiring, What type of trace would get on an oscilloscope when testing the output from a hall sensor?, Square wave, Sine wave, Saw tooth, Cosine wave, What is the main design feature of the hemispherical combustion chamber?, Only pushrods and rockers can be used, Valves are inclined at about 90° to each other , The valves are side by side, Only overhead camshafts can be used, The mass of air entering an engine is measured by the:, Air temperature and pressure in the intake manifold, Ambient temperature and air temperature in the intake, Piston speed and air temperature in the intake manifold, Speed and volume of air in the intake manifold, A cylinder leakage test could be used to diagnose, A defective spark plug, Worn crankshaft bearings, A burnt inlet valve, Excessive valve clearance, High tension plug leads have an in-built resistance, the purpose of this is to: , Improve HT strength whilst remaining flexible, Cancel any rogue signals from other HT leads, Supress radio interference, Reduce the strength of the spark, The function of an engine intercooler is to:, Cool the coolant before it re-enters the engine, Increase the density of the air, Decrease the density of the air, Regulate air flow, The output signal generated by a hall-type sensor will be a:, Sine Wave, Cosine Wave, Variable Capacitance, Square Wave, A 2-way catalytic convertor fitted to the exhaust of a compression ignition engine converts?, Hydrocarbons, oxides of nitrogen into sulphur & carbon dioxide, Oxides of nitrogen & hydrocarbons into water & carbon dioxide, Carbon dioxide and sulphur into water and carbon dioxide, Hydrocarbons and carbon monoxide into water & carbon dioxide, The purpose of exhaust gas recirculation is to:, Reduce carbon dioxide, Improve fuel economy, Reduce carbon monoxide, Reduce combustion temperature, Which of the following suppression techniques are commonly used in a HT circuit?, Resistors, Capacitors, Inductors, Bonding, Following the replacement of electronic fuel injectors. The vehicle should be tested by:, Carrying out an emissions test line with MOT requirements, Asking the customer to drive it and check for performance, Holding revs at 3000rpm and checking for fault codes, Carry out a road test and check for leaks and fault codes, A spark ignition engine misfires at all engine speeds. One fault could be:, A defective coil pack, Low resistant plug lead, Defective knock sensor, Defective crankshaft sensor, A turbo engine starts and idles but stall when the revs are increased. One fault could be:, A defective enrichment device, The fins of the intercooler blocked, A blocked air intake, A defective coolant temp sensor, High oil consumption in an engine could be caused by:, Worn crankshaft bearings, Worn compression rings, Worn pressure relief valve, Worn valve stem seals, The starter is rotating but the engine remains stationary. One fault could be:, Low cylinder compression, Worn flywheel ring gear , Open circuit starter solenoid, Open circuit starter relay, An engine misfires at all speeds. One probable fault is:, Air-filter blocked , Defective knock sensor, Defective Coil, A low resistance plug lead, When measuring the current consumption of an electric fuel pump on a fuel injection system, the meter should be:, Connected in parallel, Connected in series, Earthed to the ground, Earthed to the vehicle chassis, What would cause the valves to open too late and close too early?, Valve clearance too small, Valve clearance too large, Worn valve guides, Worn piston rings, The composition of diesel is close to:, 85% Carbon, 15% Hydrogen, 25% Carbon, 25% Petrol, 50% Hydrogen, 100% Carbon, 25% Carbon 75% Hydrogen, A multi-point fuel injection system, injects a small amount of fuel into the intake manifold continuously, Supplies low pressure fuel to the injectors, which are then operated by the engine camshaft, Has a reservoir of very high-pressure fuel which is delivered to electronically controlled injectors, Supplies high pressure fuel to the injectors in time with the engine firing order, Injects fuel into the intake manifold in time with the cylinder induction strokes, An inter-cooler is used to:, Cool the exhaust gas to decrease NOx content, Cool the inlet air to decrease its density, Cool the exhaust gas to increase the NOx content, Cool the inlet air to increase its density, Which of the following would be used to check the dynamic ignition timing on a spark ignition system?, A set of feeler gauges, A rolling torque gauge, A test light, A stroboscope, Piston strap in a light vehicle engine will be worse when:, The engine is producing black smoke, The engine is below normal temperature, The engine is at normal temperature, The engine is producing white smoke, The current consumption of an electric fuel pump can be measured by connecting the meter:, To the ground, Earthed to the vehicle chassis, In parallel, In series, For closed loop control of injector pulse width, the control unit needs a signal from the:, Boost sensor, Knock sensor, Oxygen sensor, Water temperature sensor, Checking for ovality is carried out on:, Camshaft lobes, Crankshaft journals, Timing gears, A flywheel, The output signal generated by an inductive-type sensor will be a:, Variable capacitance, Sine wave, Cosine wave, Square wave, A cylinder leakage test is to be carried out on a spark ignition engine. The position of the piston should be set at:, TDC, BDC, ABDC, BBDC, Technician A says: "a leaner air/ fuel ratio reduces hydrocarbon emissions but increases NOx" Technician B says, "additional pollution controls are used to reduce NOx" Who is correct?, Technician A, Technician B, Both are correct, Neither are correct, The air runner pipes from the plenum chamber to the cylinders on an air intake system are normally the same size and length, True, False, An engine is running and it is losing coolant from the overflow pipe. This could indicate:, The thermostat stuck in the open position, The water pump working so fast, A faulty temperature gauge allowing the engine to overheat, Internal leakage from the cylinder head gasket, Variable geometry turbochargers:, Alter the amount of fuel delivered to the injectors, Alter the speed of the exhaust gas over the turbine, Vary the amount of pressure in the exhaust using a dumb valve, Vary the speed of the exhaust by altering the waste gate.

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