6) What may cause engine overheat?Engine gets overheat when
Coolant leaks
Cooling system clogged
Weak radiator cap
Thermostat stuck shut
Inoperative electric cooling fan
Bad fan clutch, slipping fan belt, missing fan shroud
Too high or low concentration of anti-freeze
Collapsed radiator hose or debris in the radiator
Restricted exhaust system
4) Explain how timing belt works?Timing belt rests on the crankshaft pulley and either one or two camshaft pulley; they are all align through timing belt. The closing and opening of engine valves are controlled by camshaft to let in air and fuel mixture or exhaust gas, if you do not have a timing belt or damaged timing, it will directly affect the timing of opening and closing of engine valves. This is the reason it is called timing belt and if not in a good position, it will damage your engine.
Crankshaft: It is linked to the pistons by the connecting rods, the force produced by the fuel-air mixture is transmitted to the crankshaft and converted to rotary motion as the crankshaft turns.
Camshaft: It controls the intake and exhaust valves. It is linked with crankshaft either by timing chain or belt, and it turns one rotation for each two rotations of the crankshaft, for each valve it operates- the cam opens each valve at the correct time to draw fuel and air mixture or expel the exhaust gas
2) How often does a car requires services?Car requires services yearly and major
Any leakage of oil underneath the car
Check any leakage of coolant water from the radiator
Check battery condition
Check whether car emits blue gray, dense smoke or a normal smoke from exhaust pipe
Watch out for engine noises, any vibrations, lack of power or any other issues
Check for any burning smells when open the hood
Check steering wheel, driver’s seat and inner door
Check tyres ( Edge should not worn out, no bulge on the sidewall, no cuts, enough groves to hold the road)
Check all meter work fine when you start the car
10) Explain what are the components in alternator and how it works?An alternator consists of the stator, rotor and copper wiring. The rotor and stator are belt driven magnets encased in copper wiring, which creates a magnetic field. This belt is connected with engine, so when engine starts it rotates the rotor and generate a magnetic field. Stator converts this magnetic field into voltage that flows to the diode. The diode assembly converts the AC electricity to DC, which is used by car battery.
Oil pan: It is a container where engine oil settles down when car is not running
Pickup tube: When engine starts oil get sucked up through pickup tube
Oil pump: The pump will help to slide up oil into the tube against the gravity
Pressure relief valve: It relieves the pressure on oil
Oil filter: It removes dirt and debris form the oil
Spurt holes and galleries: These are the holes in the crankshaft or other parts of the engine through which oil streams and make them lubricated
Sump: Once it has lubrication job is done it will go back again into oil pan or sump
TOP 250+ Automobile Engineering Interview Questions and Answers 2019