Q.1 What is the function of differential in Car ?
The function of a differential is to transmit power from the engine to the axle that moves the wheels and allow the wheels to move at different speeds from each other.
Or in other word, We can say
With automobiles and other wheeled vehicles, the differential allows the outer drive wheel to rotate faster than the inner drive wheel during a turn. This is necessary when the vehicle turns, making the wheel that is traveling around the outside of the turning curve roll farther and faster than the other.
Q.2 What different types of smoke ?
The different color variations of smoke indicate a different set of problems.
Black Smoke :- Black smoke is the commonly emitted smoke from car on road. Which indicate the carbon emission. However there are many reason of black smoke coming out from the vehicle. First is that your engine could be burning fuel more than the usual amounts. This eventually causes your fuel to get consumed too quickly.
other reason for this is clogged air filters. Dirty air filters do not let clean air get in the combustion chamber. Faulty fuel injector can also contribute to black smoke. In addition, if your car has faulty sensors, it can give false pressure readings and result in excessive injection of fuel.
White Smoke : White smoke is mainly comes out from the vehicle when your vehicle gets overheated due to cooling system not working properly. We use coolant or antifreeze in coolant system to maintain the temperature of the vehicle or to avoid overheating of the vehicle, sometimes this coolant comes into the cylinder by faulty gasket and coolant also burnt with the fuel which can cause overheating and white smoke.
Or in other word we can say..
This is one of the most common kinds of smoke witnessed from those cars which are ill-maintained, the reasons behind which are lack of engine oil, damaged engine gasket or broken engine block or cylinder. The root cause behind this is the faster wear and tear of engine components due to improper lubrication, which in turns result in overheating and emission of white smoke.
Blue Smoke : If you see blue smoke coming out of your car’s tailpipe, it clearly indicates that the oil in your engine is getting burned. It happens when the oil starts leaking from the place it passes by, and instead of lubricating the parts for smooth movement, it is leaking out somewhere else and leaving the essential parts dry. It might also happen the oil is seeping into the fuel tanks and getting mixed with it, and might even be combusting with it, in the process. This happens mainly in the case when the piston rings or gaskets are worn out, or the PCV valve is not working properly. If you continue using the car with oil leakage, it can damage your car’s spark plugs.
or in other word we can say
When your car emits blue smoke from its exhaust pipe, chances are that there is a possible leakage of engine oil within the engine. This leakage usually happens as a result of damages caused to cylinder walls, piston rings or valve seals. If the smoke emerges during acceleration, the reason is most possibly related to the cylinder head, and during deceleration, it is due to damaged piston rings.
Gray Smoke : This happens due to a multiple of reasons happening under the hood of your car, such as burning of transmission fluid, or a faulty turbocharger, the latter of which is a very common reason with diesel engines emitting grey smoke. In such cases, the exhaust pipe usually emits grey coloured smoke which has a burning smell to it.
Gray smoke can be ambiguous sometimes. There is a turbocharger in your cars. Its task is to increase your car’s engine efficiency by pulling more air from the gas chambers and allowing it to drive the turbine to burn fuel efficiently. However, sometimes a bad or failing turbo charger can result in incomplete combustion. Gray smoke and blue smoke usually have similar causes, that is, burning oil.
Gray smoke can also be forming because of auto transmission fluid. Auto transmission fluid is used to keep the car’s internal components lubricated. Its main function is to keep the car’s cooling system running properly, to prevent the metallic components from wearing out and keep the gaskets in proper working condition. But, if you have a broken transmission modulator, it can make the transmission fluid leak into the combustion chambers and get burned up.
Another cause according to our experts can be a jammed PCV valve. The function of a PCV valve is to pump air and gas through the tubes into the combustion chambers. The PCV system (Positive Crankcase Ventilation) also reduces toxic emissions and sends them back to where combustion takes place. However, if there is a broken or jammed PCV valve, it can make the air and gas get stuck inside the ventilation system and result in pressure build up, which in turn leads to leakages.
Q.3 What is the use of left feet in the automatic car?
- For general driving in an automatic car, use only your right foot for operating either the accelerator or brake pedal.
- When carrying out manoeuvres or moving off on a hill in an automatic car, you can use both feet; the right foot to operate the accelerator pedal and the left foot to operate the brake pedal.
For general driving in an automatic car, you use only your right foot for operating either the accelerator pedal or the brake pedal as there’s no need to brake and accelerate at the same time. While it is possible to use both feet when driving an automatic car, there are potential hazards associated with it. These include:
- In an emergency situation, you’re at greater risk of fully depressing both the brake and the accelerator.
- Some drivers have a tendency to ‘ride’ the brake pedal. This means that they rest their left foot on the brake pedal. As the brake pedal only needs to be slightly touched to activate the brake lights, the driver may inadvertently activate them.
- Incorrect combined use of both the brake and accelerator pedals can result in conflict, meaning that there’ll be a certain amount of simultaneous braking and accelerating. Over time, this results in greater fuel consumption and brake wear.
- If you have previous experience driving a manual car, you’ll use your left foot to operate the clutch. This means that if you use your left foot to operate the brake in an automatic car, from muscle memory and habit, you may use it as though it’s the clutch pedal.
Q. 4 What is the position of the valve in the compression stroke of a 4 stroke engine ?
Both Valve Remain Close
Q.5 Explain the working of the 4 Stroke Engine ?
Q.6 What is Engine Firing Order ? Why is it very important ?
Ans: Engines cylinders don’t fire in the sequence of 1-2-3-4-5-6 and so on. It could cause the crankshaft to deform or break. So, manufacturers shuffle the combustion in such a way that it creates power balance in the engine. The order or sequence in which the engine cylinders fire or generate & deliver power is called the engine firing order.
Firing order is a critical parameter to get optimum performance of an engine. The order will affect the amount of vibration, generation of back pressure, proper balancing of the engine, smooth flow of power, and the cooling rate of the engine.
- Typical firing orders of four cylinder engine are- 1-3-4-2, 1-4-3-2, 1-4-2-3 etc.
- Typical firing orders of five cylinder engines are- 1-2-4-5-3 , 1-4-5-2-4 etc.
- Typical firing orders of six cylinder engines are- 1-3-5-2-4-6, 1-4-2-5-3-6 etc.
Following are some firing orders used by automobiles:
- 1-2-3 for perodua engine
- 1-3-2 for BMW K75 engine, Subaru Justy engine
- 1-3-2-4 for Ford Taunus V4 engine
- 1-2-4-3 for British Ford and relay engine
- 1-3-2-4 for Yamaha R1 cross-plane, Subaru 4-cylinder engines
- 1-4-3-2 for Volkswagen air-cooled engine
- 1-2-4-5-3 for Straight-five engine, Volvo 850, Audi 100
- 1-3-5-4-2 for GM Atlas engine
- 1-5-3-6-2-4 for Volkswagen VR6 engine, Opel Omega A, Nissan L Engine
- 1-4-3-6-2-5 for Mercedes-Benz M272 engine
- 1-6-5-4-3-2 for GM 3800 engine, Rover KV6 engine
- 1-2-3-4-5-6 for Chrysler Pentastar engine
- 1-4-2-5-3-6 for Ford Cologne V6 engine, Ford Essex V6 engine (UK)
- 1-4-2-6-3-5 for Toyota HZ engine.
Q.7. How many types of Pillars in Cars ?
There are three main pillars supporting the frame work of a typical vehicle and these includes A-pillar, B-pillar and C-pillar, but some vehicles with very large compartment has additional pillar supporting structure at its rare side known as D pillar.
Car pillars are components that support the structure of an enclosed automobile body. This is similar to that of a house with pillars supporting the roof over the floor. Car pillars are designed to stand in near vertical or inclined positions to support the roof.
Q. Name some body part of car ?
- Body shell
- Hood or bonnet
- Front bumper
- Rear bumper
- Bumper grille
- Crash guard or bullbar
- Head light
- Fog lamp
- Indicator lights
- Wiper blade
- Radiator supports
- Cowl panel
- Quarter panel
- Fender liners
- Door handle
- Window glass
- Quarter window
- Trunk or decklids
- Mud flaps
- Number plate
- Tail lights
Q. 9 How many types of car insurance ?
Mainly there are three types of motor insurance : –
There are three different types of insurance – Private Car Insurance, Two-wheeler Insurance, and Commercial Vehicle Insurance.
Liability car insurance
Liability car insurance helps financially protect the other party when you’re at fault in a car accident. It includes two types of coverage: bodily injury (BI) and property damage (PD). BI pays for expenses that result from injuries sustained in an accident, while PD pays for damaged property.
Liability insurance limits are typically written as three numbers in this format: 25/50/10.
Physical damage car insurance
When your vehicle is damaged in an accident or by a fallen tree branch, physical damage car insurance covers your repair costs. It consists of two types of coverages, collision and comprehensive, which are differentiated by the circumstances under which your car was damaged.
Some insurance providers, such as AAA, extend liability insurance coverage to rental cars. Before paying extra for the rental company’s car insurance, double check with your own insurer first. Keep in mind: This coverage is different from car rental reimbursement insurance, which is an optional coverage that pays for a temporary rental while your car is in the body repair shop.
No-fault or personal injury protection
Personal injury protection (PIP) pays for medical expenses for you and passengers in your car when you get into a car accident. It’s also called “no-fault insurance” because it covers your injuries regardless of who is at fault in the accident. Beyond hospital expenses, PIP will sometimes cover lost wages, household expenses and even funeral costs. PIP is mandatory in some states, such as New York and Michigan, and optional in others.