Class 11 Automotive Service Technician Chapter 5 Regular Maintenance of an Engine Solutions English Medium As Per AHSEC New Syllabus to each chapter is provided in the list so that you can easily browse through different chapters Class 11 Automotive Service Technician Chapter 5 Regular Maintenance of an Engine Question Answer and select need one. Class 11 Automotive Service Technician Chapter 5 Regular Maintenance of an Engine Notes Download PDF. AHSEC Class 11 Automotive Service Technician Question Answer English Medium.
Class 11 Automotive Service Technician Chapter 5 Regular Maintenance of an Engine
Also, you can read the NCERT book online in these sections Solutions by Expert Teachers as per Central Board of Secondary Education (CBSE) Book guidelines. Class 11 Automotive Service Technician Chapter 5 Regular Maintenance of an Engine Textual Solutions are part of All Subject Solutions. Here we have given AHSEC Class 11 Automotive Service Technician Chapter 5 Regular Maintenance of an Engine Textbook Solutions English Medium for All Chapters, You can practice these here.
Regular Maintenance of an Engine
Chapter: 5
| SESSION 1: INSPECTION OF AN ENGINE |
| Check Your Progress |
A. Fill in the blanks:
1. For fuel leakage ______________, ______________ and ______________ must be checked in the engine.
Ans: Fuel tank exit, tank cap or rubber washer, loose fuel filter.
2. Check the hose pipe for ______________ or deterioration.
Ans: Distortion.
3. Inspect the radiator cap, neck and radiator core for ______________ leakage.
Ans: Coolant.
4. Inspect radiator hose clips for _____________, if leakage is noticed, ______________ the clips.
Ans: Looseness, tighten.
B. Multiple choice questions:
1. What is the power producing unit in an Automobile System?
(a) Engine.
(b) Chassis.
(c) Piston.
(d) Connecting rod.
Ans: (a) Engine.
2. Which colour indicates that there are chances of coolant leakage?
(a) Green.
(b) Blue.
(c) Yellow.
(d) None of the above.
Ans: (a) Green.
3. Engine is where fuel is burnt to create heat energy and that heat energy is converted into ____________________.
(a) Kinetic energy.
(b) Dynamic Energy.
(c) Static energy.
(d) Thermal energy.
Ans: (a) Kinetic energy.
C. Answer the following questions:
1. Why must leakages be controlled?
Ans: One must regularly check the engine for leakages as:
(i) The leakage of combustible gases can reduce the mileage and pick-up.
(ii) The leakage of coolants can affect the engine’s temperature and cause overheating, due to which the parts can deteriorate.
(iii) The leakage of the lubricating oil can increase the friction and reduce the engine’s power output. Such leakages must be repaired in time to avoid failure of the engine.
2. What are the steps to be followed while checking the leakages in an engine?
Ans: Selective Procedure to Check the Leakage in a Vehicle’s Engine:
(i) Keep the vehicle on a hard surface.
(ii) Open the engine bonnet and support it with a lever.
(iii) Inspect for external leakage of oil, coolant, gases, locate the area.
(iv) Inspect coolant tank and its connections.
(v) Inspect radiator hose clips for looseness and if leakage is noticed, tighten the clips.
(vi) Check hose pipeline for distortion and deterioration and replace.
(vii) Inspect radiator cap, neck and radiator core for coolant leakage.
(viii) Inspect torn thermostat housing gasket, which may cause leakage.
(ix) Inspect water pump seals and gaskets for coolant leakage.
(x) In case of fuel leakage inspect fuel tank exit, tank cap, rubber washer, flexible fuel line for slackness, torn fuel filter gasket, loose fuel filter, fuel pump connections, connectors, loose connections at nozzle or carburettor areas.
(xi) Combustion gases leakage can be traced by noticing black soot around cylinder head and block, torn cylinder head gasket, spark plug or nozzle, engine induction and exhaust manifold, valve guide or improper tappet clearance.
(xii) For lubricating oil leakage, set newspaper under engine, run engine for 5 minutes (without moving vehicle), locate spots on newspaper and fix leakage by replacing gasket, oil seal, etc.
| SESSION 2: WASHING OF AN ENGINE |
| Check Your Progress |
A. Fill in the blanks:
1. Latest engines are_______________ and fitted in a small area.
Ans: Compact.
2. ____________ is used for washing the engine.
Ans: Diesel sprayer.
3. Spray ____________ and remove the oily layers and muck water from an ____________.
Ans: Water, engine.
4. Liquid soap should be applied slowly in the ____________ where the hand can reach.
Ans: Area.
5. Do not clean the ____________ when it is hot.
Ans: Engine.
B. Multiple Choice Questions:
1. Which of these is required to clean the engine?
(a) Car washer.
(b) Compressor.
(c) Diesel sprayer gun.
(d) All of the above.
Ans: (d) All of the above.
2. What are the steps to clean or wash the engine?
(a) Keep the vehicle on hard surface.
(b) Unlock the engine bonnet and hold up it properly.
(c) Allow the engine to reach atmospheric temperature.
(d) All of the above.
Ans: (d) All of the above.
3. What type of precaution should be taken for washing of engine?
(a) Do not use high pressure to clean engine.
(b) Safeguard sensors, spark plugs, nozzle, and electronic gadgets from water.
(c) Do not give water pressure when engine is in running condition.
(d) All of the above.
Ans: (d) All of the above.
C. Answer the following questions:
1. Why is washing the engine necessary?
Ans: The latest engines are compact and fitted in a small area. It is necessary to clean the engine at regular intervals to take away oily layers, depositions of muck (mud and water), which may cause the engine heat and deteriorate its performance.
2. List the steps to be followed while washing the engine.
Ans: Steps to clean or wash the engine:
(i) Keep the vehicle on a hard surface.
(ii) Unlock the engine bonnet and support it with a lever.
(iii) Inspect for external leakage of oil, coolant, gases, locate the area.
(iv) Allow the engine to reach atmospheric temperature.
(v) Separate the negative terminal of the battery for protection.
(vi) Use a diesel sprayer and spray only on oily layers of the engine.
(vii) Control the car washer and set the water spraying nozzle at a low force.
(viii) Spray the water and remove the oily layers and muck water from the engine.
(ix) Take some liquid soap and apply the soap gradually in the area where the hand can reach.
(x) Clean the engine externally with low water pressure.
(xi) Also clean the bonnet area and engine room.
(xii) Start the compressor and give air pressure to remove the water from the electrical and electronic gadgets.
(xiii) Allow the engine to dry.
(xiv) Connect the battery terminal and start the engine, checking for smooth working.
| SESSION 3: TUNING FUEL SYSTEM OF AN ENGINE |
| Check Your Progress |
A. Fill in the blanks:
1. _____________ is the adjustment or modification of the internal combustion engine.
Ans: Engine tuning.
2. Warm up the _________ and turn the idle speed screw in __________ direction to increase the engine’s RPM.
Ans: Engine, clockwise.
3. Use _____________ to read RPM.
Ans: Tachometer.
4. Injector or nozzle is used in a(an) __________.
Ans: Engine.
B. Multiple choice questions:
1. ____________ is the adjustment or modification of the internal combustion engine.
(a) Tuning.
(b) Fuel system.
(c) Ignition system.
(d) Cooling system.
Ans: (a) Tuning.
2. Which of these is a step for fuel tuning?
(a) Clean air cleaner and fuel filter regularly.
(b) Remove the tank cap.
(c) Inspect the rubber washer.
(d) All of the above.
Ans: (d) All of the above.
3. Which of these is a step of nozzle pressure test?
(a) Remove the injector or nozzle from an engine.
(b) Hold container and lower the injector or nozzle.
(c) Join the fuel pipe to the nozzle and start the engine.
(d) All of the above.
Ans: (d) All of the above.
C. Answer the following questions:
1. Why is tuning necessary?
Ans: Engine tuning is the adjustment or modification of the internal combustion engine or Engine Control Unit (ECU) to yield optimal performance and increase the engine’s power output, economy, or durability.
2. What are the steps to be followed while tuning the fuel system?
Ans: Steps for fuel tuning:
(i) Clean air cleaner and fuel filter regularly.
(ii) Remove the tank cap.
(iii) Inspect the rubber washer.
(iv) Clean the vent hole to maintain atmospheric pressure on the fuel.
(v) Inspect the fuel line for leakage, and if the flexible fuel line is damaged, replace it immediately.
(vi) Inspect the suction or vacuum of the fuel pump.
(vii) Check the fuel pump pressure and compare the reading with the specifications in the service manual.
3. What are the advantages of tuning?
Ans: Engine tuning offers the following advantages:
(i) Increased power output: The engine will produce more power, improving the vehicle’s performance.
(ii) Better fuel efficiency: It helps in optimizing the fuel consumption and gives better mileage.
(iii) Improved durability: The engine runs more smoothly, reducing wear and tear, thus enhancing the life of the engine.
(iv) Increased Fuel Efficiency: Proper tuning can reduce fuel consumption.
(v) Enhanced Smoothness: Smoother engine operation, reducing vibrations.
| SESSION 4: TUNING OF IGNITION SYSTEM OF AN ENGINE |
| Check Your Progress |
A. Fill in the blanks:
1. The ignition system plays an important role in process of __________________.
Ans: Combustion.
2. Ignition system is classified in two ways ___________ circuit with LT leads and _____________ circuit with HT leads.
Ans: Primary, secondary.
B. Multiple choice questions:
1. The ignition system converts current from ______________________.
(a) 12 volt to 20,000 volt.
(b) 13 volt to 40,000 volt.
(c) 14 volt to 30000 volt.
(d) None of the above.
Ans: (a) 12 volt to 20,000 volt.
2. Thin wires and their connections supply current between 12 volt and are called __________________.
(a) Low tension leads.
(b) High tension leads.
(c) Multi volts.
(d) None of the above.
Ans: (a) Low tension leads.
3. The thick wires supply current of 20–25,000 volt and are called _______________.
(a) High Tension Leads.
(b) Low Tension Leads.
(c) 12volt to 20,000 volt.
(d) All of the above.
Ans: (a) High Tension Leads.
C. Answer the following questions:
1. Why is tuning of ignition system of engine necessary?
Ans: The ignition system plays an important role in the process of combustion. The system converts current from 12 volt to 20,000 volt. To ignite the charge, the advanced spark or retarded spark leads to imbalanced combustion, which in turn affects the engine’s performance and changes the engine tune. Therefore, proper tuning of the ignition system is necessary to ensure balanced combustion and to maintain engine performance.
2. What are the steps to be followed while tuning the ignition system of an engine?
Ans: Basic Steps for Tuning of Ignition System:
(i) Inspect loose contact of the battery terminal.
(ii) Inspect the socket connection for slackness.
(iii) Check the connection to the ignition switch.
(iv) Check the primary circuit of the LT lead while inspecting the connection.
(v) Inspect the connection with the pick-up coil and CDI unit.
(vi) Disconnect the spark plug connection.
(vii) Remove the distributor cap and check the HT lead for loose connections.
(viii) Check slot machine contact points for erosion or burn.
(ix) Inspect the working of the spark advance mechanism.
(x) Clean the distributor cap and fix it properly.
(xi) Using the appropriate spanner, loosen the spark plug slowly from each cylinder.
(xii) Inspect the spark plug condition:
– Black soot: rich mixture – cold engine.
– Dead white soot: lean mixture – hot engine.
– Brownish color: normal.
(xiii) Check for an eroded central electrode and make it straight to maintain the air gap.
(xiv) Check for deposition and clean the plug with a sand blast machine or emery paper.
(xv) Using a wire feeler gauge, set the spark plug gap as per the specification.
(xvi) Clean the spark plug threads.
(xvii) Apply oil and check spark plug sealing gasket washer, if needed replace it.
(xviii) To install the plug, first fix it by hand.
(xix) Thread it smoothly and tighten the same with specified torque.
(xx) Connect the lead wire with the plug.
(xxi) Start the engine and check the engine sound and ascertain if there is any change in engine sound.
| SESSION 5: TUNING OF LUBRICATION SYSTEM OF AN ENGINE |
| Check Your Progress |
A. Fill in the blanks:
1. _____________ is used for lubricating the engine of a vehicle.
Ans: Pressurised lubrication system.
2. The lack of __________ may lead to a noisy engine and also change the _________ of the engine due to increase in ___________.
Ans: Lubrication, tune, friction.
3. Change the __________ oil, if it loses viscosity or after recommended distance of __________.
Ans: Lubricating, interval of distance in kilometres .
B. Multiple choice questions:
1. The engine lubrication system works on _____________.
(a) Pressurised lubrication system.
(b) Compressed air system.
(c) Mixed hydraulic system.
(d) None of the above.
Ans: (a) Pressurised lubrication system.
2. The role of oil filters and oil strainer in engine lubrication system is to __________.
(a) Filter the circulated lubricating oil.
(b) Filter the circulated fuel.
(c) Filter the circulated air-fuel mixture.
(d) None of the above.
Ans: (a) Filter the circulated lubricating oil.
3. If oil quality is good, it means ____________.
(a) Viscosity is high.
(b) Pressure is low.
(c) Lack of viscosity.
(d) None of the above.
Ans: (a) Viscosity is high.
C. Answer the following questions:
1. Why is engine lubrication necessary?
Ans: Lubrication plays a key role in the life expectancy of an automotive engine. It reduces wear or friction, heat, and cleans engine parts, gives a cushioning effect, and fills the gap. Lack of lubrication can lead to noisy engine operation and change the tune of the engine due to increased friction. Therefore, it is necessary to check the lubricating oil at specified intervals, change it if it loses viscosity, or after the recommended interval of distance in kilometers.
2. What are the steps to be followed while checking the lubrication system?
Ans: Steps to be followed while checking the lubrication system:
(i) Slowly remove the dipstick from the sump and wipe it with cotton waste.
(ii) Check the oil level on the dipstick. If it is low, check the quality of the oil.
(iii) If the oil is thick, it has better viscosity; add oil for the proper level.
(iv) If the oil is black, it lacks viscosity. Change the oil and oil filter.
(v) Bring the vehicle to the lubrication bay and place the container below the drain plug.
(vi) Use specified spanners to loosen the drain plug and drain the oil into the container.
(vii) Switch on the engine for 3 seconds so that it becomes warm and the oil in the engine pores drains easily.
(viii) Fix the drain plug with a new washer and tighten it with the specified torque.
(ix) Refill the lubricating oil through the filler plug with the recommended quantity and quality.
(x) Check the oil pressure on the pressure gauge and compare it with the service manual specifications.
3. Why do leakages occur in lubrication systems?
Ans: Leakages in lubrication systems occur due to several reasons, including:
(i) Worn out seals or gaskets: These components can degrade over time, causing oil to leak.
(ii) Improper installation: Incorrect installation of parts such as oil seals and gaskets can result in leakage.
(iii) Pressure Issues: Excessive pressure or pressure
(iv) Pressure Issues: Excessive pressure or pressure.
(v) Old or degraded oil: Oil that has degraded over time can lose its viscosity and may not seal properly, leading to leaks.
(vi) Corrosion: Corrosion of system components.
| SESSION 6: TUNING OF COOLING SYSTEM OF AN ENGINE |
| Check Your Progress |
A. Fill in the blanks:
1. _______ is used for cooling the vehicle.
Ans: Coolant.
2. Normal temperature of an engine is in the range of ___________.
Ans: 75 and 80 Degree.
3. The percentage of heat removed by the cooling system is _________.
Ans: 30%.
B. Multiple choice questions:
1. Cooling system in a car protects the engine from ______________.
(a) Overheating.
(b) Water heating.
(c) Overflow.
(d) None of the above.
Ans: (a) Overheating.
2. Which of the following is not a part of the cooling system?
(a) Water jacket.
(b) Water pump.
(c) Radiator and radiator cap.
(d) Axle.
Ans: (d) Axle.
3. Cooling fan belt tension is ______________.
(a) 6–7 mm as deflection.
(b) 7–10 mm as deflection.
(c) 10–60 mm as deflection.
(d) All of the above.
Ans: (b) 7–10 mm as deflection.
C. Answer the following question:
1. Why is cooling of an engine necessary?
Ans: An efficient cooling system is essential for protecting the engine and removing 30% of the engine’s heat. Overheating can lead to poor performance, distortion of components, and a shorter engine life. Therefore, regular checks on the cooling system and coolant levels at specified intervals are necessary. During summer, these checks should be more frequent.
2. What are the steps to be followed while checking the functioning of the cooling system?
Ans: The steps to be followed while checking the functioning of the cooling system are as under:
(i) Reading of Temperature Gauge: The temperature gauge is fixed on the dashboard, which regularly monitors the variation in engine temperature. The moderate temperature of the engine should be 75–80 degrees Celsius, which needs to be maintained.
(ii) Parts of Cooling System: The cooling system of an engine includes the engine’s water jacket, water pump, radiator, radiator cap, cooling fan, thermostat, hoses, heater core, and overflow tank.
(iii) Checking Circulation of Water in Cooling System:
(a) Switch off the ignition switch of the vehicle.
(b) Remove the negative terminal from the battery.
(c) Turn the upper radiator cap slowly and allow the steam or water vapor to release from the radiator.
(d) Turn the radiator cap and remove it from the neck of the radiator.
(e) Connect the battery terminal and switch on the ignition.
(f) Start the engine at idle speed.
(g) Inspect the circulation of water in the radiator.
(h) Circulation of water should be observed as the rate of inlet must be equal to the rate of outlet of the coolant.
(iv) Checking for Coolant Leakage:
(a) Inspect the coolant tank and its connections.
(b) Inspect radiator hose clips for looseness and tighten them if leakage is noticed.
(c) Check the hose pipe for distortion or deterioration and replace if necessary.
(d) Inspect the radiator cap, neck, and radiator core for coolant leakage.
(e) Inspect for torn thermostat housing gasket for leakage.
(f) Inspect the water pump seals and gaskets for leakage of coolant.
| SESSION 7: TIGHTENING OF FASTENERS (NUTS, BOLTS AND SCREW) |
| Check Your Progress |
A. Fill in the blanks:
1. Tightening of cylinder head is required to avoid _______.
Ans: Combustion gases .
2. Loose induction manifold may cause emission _________.
Ans: Leakage.
B. Multiple choice questions:
1. Loose induction manifold may create _________________.
(a) Vacuum leakage.
(b) Pressure leakage.
(c) Hydraulic leakage.
(d) None of the above.
Ans: (a) Vacuum leakage.
2. Loose induction manifold may cause _________________.
(a) Emission leakage.
(b) Vacuum leakage.
(c) Both of the above.
(d) None of the above.
Ans: (a) Emission leakage.
3. The material and tools required for tightening of fastener include __________________.
(a) Socket spanner.
(b) Tommy bar.
(c) Extension bar or rod.
(d) All of the above.
Ans: (d) All of the above.
4. Mallet is made of _______________.
(a) Iron.
(b) Wood.
(c) Steel.
(d) Aluminium.
Ans: (c) Steel.
C. Answer the following questions:
1. What are the different types of tools used in tightening of fasteners?
Ans: The different types of tools used in tightening of fasteners are:
(i) Socket spanner.
(ii) Tommey bar.
(iii) Extension bar or rod.
(iv) Torque wrench.
(v) Torque wrench socket.
2. How is the torque wrench set?
Ans: To set a torque wrench:
(i) Unlock the Handle: If your torque wrench has a locking mechanism, unlock it to adjust the setting.
(ii) Selecting the desired unit: Choosing the unit of measurement (e.g., Nm, ft-lbs, in-lbs).
(iii) Lock the Handle: Once the desired torque value is set, lock the handle in place to prevent it from shifting during use.
(iv) Verifying the setting: Double-checking the set torque value.
3. List the steps used in tightening.
Ans: The steps used in tightening are as under:
(i) Remove the tappet cover from the cylinder head.
(ii) Remove the rocker arm assembly.
(iii) Slowly remove the pushrods (overhead valve mechanism).
(iv) Use a specific size of socket spanner with the appropriate torque wrench.
(v) Strictly use the service manual as per the prescribed sequence.
(v) Tighten the cylinder with a specified torque.
| SESSION 8: ENGINE TIMING (TUNING) |
| Check Your Progress |
A. Fill in the blanks:
1. Valve timing is used for _____________.
Ans: Fuel supply.
2. Ignition timing helps in _____________ of an engine.
Ans: Opening and closing.
3. Injection timing is used _____________.
Ans: Injecting fuel.
4. Stroboscope helps in _____________ of ignition timing.
Ans: Checking.
B. Multiple choice questions:
1. Which component is used in timing lights to dynamically set the explosion timing of an otto cycle combustion engine?
(a) Stroboscope Lamp or Gun.
(b) Piston.
(c) Ring.
(d) Rotary.
Ans: (a) Stroboscope Lamp or Gun.
2. The fuel injector injects the fuel at the right time at the end of ___________________.
(a) Suction stroke.
(b) Compression Stroke.
(c) Expansion Stroke.
(d) Exhaust.
Ans: (b) Compression Stroke.
3. Full foam of MPFI system ______ ______ ______ _________.
(a) Multi Point Fuel Injection.
(b) Multi Fuel Point Injection.
(c) Multi Point Fuel Induction.
(d) None of the above.
Ans: a) Multi Point Fuel Injection.
4. What is the full form of CVTI?
(a) Charged Motion Variable Time Ignition.
(b) Changed Motion Variable Time Ignition.
(c) Combustion Motion Variable Time Ignition.
(d) All of the above.
Ans: (a) Charged Motion Variable Time Ignition.
C. Answer the following questions:
1. What is meaning of timing?
Ans: Timing refers to the process of coordinating and managing the operations of various components in an engine to ensure that they work together efficiently and effectively. Timing means making sure the engine’s parts work together at the right moments. It controls when the valves open and close, matching the movement of the pistons. This helps the engine run smoothly, use less fuel, and give more power.
2. Give the differences between ignition and injection timing.
Ans: The differences between ignition and injection timing are as under:
| Ignition Timing | Injection Timing |
| Timing of the spark to ignite the fuel-air mixture. | Timing of when fuel is injected into the combustion chamber. |
| To initiate combustion at the optimal point in the piston’s stroke for maximum power, fuel efficiency, and reduced emissions. | To deliver the correct amount of fuel at the right time for efficient combustion, considering engine speed, load, and desired power output. |
| Spark-ignition engines (gasoline engines). | Compression-ignition engines (diesel engines) and some gasoline engines with fuel injection. |
| Affects power, fuel efficiency, and combustion smoothness. | Affects fuel efficiency, power output, and emissions. |
| Primarily applicable to Spark-Ignition (SI) engines (e.g., gasoline engines). | Applicable to Diesel engines and Gasoline Direct Injection (GDI) engines. |
3. Name tool used in checking engine timing.
Ans: The tool used in checking engine timing is Stroboscope Lamp or Gun.
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