What are the symptoms of a burnt exhaust valve?
The symptom you’re likely to notice the most when you have a burnt exhaust valve is a loss of power from the engine and an increase of fuel consumption as the engine is run harder to do the work expected of it. Other symptoms will be dependent upon how badly burn the valve is. You’ll be looking at a valve job to correct it, or else swap out the cylinder head altogether.When the edges of an exhaust valve burn, the combustion chamber no longer seals and not only do you lose compression in that cylinder, unburnt hydrocarbons will be exiting before they can be ignited.Running an engine low on oil will often burn one or more valves before the main bearings start to pound. Otherwise, a lean fuel mixture can cause this, too.On modern vehicles with a full exhaust system, the sound can be hard to discern. However, a cylinder leakage test will pinpoint it fairly well. Your pressure loss will be fairly high and you’ll hear the pressurized air escaping through the exhaust system, rather than through the intake or the crankcase. If you hook up a vacuum gauge, you may notice a steady loss of vacuum at idle if a valve is burnt or sticking.
What causes black smoke in petrol cars?
Black smoke in the exhaust of petrol (gasoline) powered cars is caused by incomplete combustion of hydrocarbon fuel resulting in black carbon particles. Incomplete combustion is mainly caused by too much fuel for the amount of air available, or by fouled fuel injectors that don’t properly atomize the fuel. Too much fuel is caused by faults in the fuel injection control system that includes fuel pressure regulators, air volume and temperature sensors, and the engine control computer.
Why does a camshaft in a four-stroke engine rotate at half the speed of the crankshaft?
It’s a 4 stroke engine This is a bit simplified but lets start with the piston at the top. 1st stroke The piston moves down, the intake valve opens . 2nd stroke. The intake valve closes, the piston moves up. The crankshaft has rotated once and one valve has opened.3rs stroke. The spark plug fires the mixture, the piston moves down. 4th stroke. The exhaust valve opens, the piston moves up. The engine has completes 2 revolutions and each valve has opened once. The camshaft travels at half the crankshaft speed because each valve opens only one every two revolutions of the crankshaft.
What are the possible chances for diesel mixing with lub oil in a six cylinder inline diesel Engine?
The probable ways through which engine oil gets diesel contamination isThrough blow-by of combustion gasses: practically 100% sealing by the rings is impossible. Normally a diesel engine works with 93% to 98% sealing at max engine load to minimum engine load at running temperature ( Cold diesel engines will blow by more due clearance in cold condition) considering it to be a new engine with defined tolerances. so there is always leaking combustion gasses into the crank case . diesel oil on the surface of rings do not burn hence due to leakage the diesel is forced into crank case by combustion pressures. due to high temperatures the diesel is in vapor state and sent again to combustion chamber by breather port. during this process a slight amount of diesel contamination normally occurs due to condensation of diesel vapor on contact with oil in crankcase.improper injection: If the diesel injector is not atomizing the fuel properly due to lack of pressure , leaking injector nozzle lower compression pressure( due to leaking valve/compression rings) then we have unburnt diesel contents at higher levels leading to more diesel contamination level in lube oil.engines with high rpm hours on its clock will experience higher diesel contamination due to the existence of all the above said criteria due to worn out parts creating large clearances leading to extensive leaking in every possible way !
Which engine is more powerful Diesel or petrol?
Ganesh Madiwal has got some points right but made a few mistakes as well:The petrol (gasoline) engine is much cheaper to maintain than its equivalent diesel counterpart.Petrol engines are not meant for luxury cars; rather they are meant for all cars. Perhaps Ganesh is unaware of the fact that the smallest/cheapest cars are all petrol variants.Now which engine is better? The answer to this depends upon use:If you are mostly driving in the city with lot of short rides, then petrol is suitable. Diesel is suitable for long continuous rides. This is because the start of diesel engine puts the engine at a huge compression to ignite the fuel. While petrol engine ignites the fuel (petrol) by spark plugs, the diesel engine ignites the diesel by huge compression, overheating the fuel-air mixture and thus taking it beyond the ignition point.Because the diesel engine uses compression, it must be much more sturdy, heavy built. Diesel engines are thus expensive to manufacture. That is why diesel cars are more expensive than petrol cars.Because of the heavy engine, the tyres of the car need to be one grade higher and even then wear out faster than in the petrol variant.Diesel fuel yields better fuel economy because ml to ml it burns more complete and produces more force. Diesel yields more torque and therefore ideally suited for heavy vehicles (like SUVs and trucks).Diesel engine is noisier. To cut down in cabin noise, the car needs to have extra dampening and insulation. This also adds to the weight of the car or the car is too noisy.Although diesel is cheaper than petrol, the cost difference between similar variants of petrol and diesel could be anything for ₹ 100,000 to ₹ 250,000. If you buy petrol car means you are getting petrol worth ₹ 100,000 to ₹ 250,000 free. Think about that!(Diesel is cheaper than petrol only in India; at all other places diesel is more expensive. The Indian Govt. is slowly bringing parity between the prices. In 2005 or earlier, diesel was half the price of petrol.)So in a nutshell:There are advantages and disadvantages on both sides.Think of petrol if you drive less than 10,000 km per year and mostly city with short rides. Think diesel otherwise.
What would happen if I push the start/stop button on my car while the car is running? Would it cause any harm to my car engine?
Adding to Matt's answer:Usually, one press won't turn off your engine; your car thinks you probably just made a mistake and will continue humming along. But some cars (such as the Volt) will ask for a confirmation, and if you press the start button again within a certain timeframe, the car will shut down. Other cars (such as the Prius) will shut down if you press and hold the start button.
Why does a car lose power and can't climb a hill?
Spark plugs, brakes, exhaust, tyres, gearbox, clutch, auto transmission, throttle linkage, fuel pressure, fuel injectors, air filter, carburetor, radiator, valves, compression are some of the reasons.To eliminate the brakes. Leave it in neutral with the handbrake off and just push the car forward. Do not do this standing in front of the car at the top of a steep hill or on the edge of a cliff.Spark Plugs, valves. Listen to the engine exhaust with the car in neutral. If it sounds off-beat and irregular it may have a speak plug out or a valve not holding compression. Do not put your ear by the exhaust while your friend who is off his head is controlling the accelerator.Clutch. Put the car in gear with all the family in it and drive up a hill. If the engine revs and the car does not go forward the clutch or auto transmission may be slipping. Caution. Make sure the handbrake works before doing this.Fuel. Make sure the engine is receiving fuel. Rather than pull off a fuel hose whilst smoking a cigarette ask a mechanic to check fuel pressure.Unless it is a spark plug out it would be better to ask a mechanic to check it.
Why does my car lose power going uphill?
Your car doesn't lose power when going uphill. For a set rev range in a set gear your car has the same amount of power on the flat as it does going uphill.This is the problem, because going uphill you have an increased effect of gravity acting on the mass of your vehicle i.e gravity is trying to pull your vehicle downhill as you progress up the hill.This is a net increase in the forces working against your car and your car's engine. If you're approaching a hill that you know that your car struggles on then you probably need to drop a gear and increase the rev range that you're using as you proceed up the hill.You probably already noticed that your vehicle gained power as you go down hill and you possibly need little or no throttle at all. This is because gravity is now pulling the mass of your vehicle downhill, a net decrease in the forces working against your car.As a general rule of thumb which ever gear you need to use to comfortably get up a hill, is the same gear that you should be using to comfortably and safely get down a hill.
Does your air conditioning in your car affect your car’s speed?
If alternator is running on Engine (most cases) : Depends on manufacturer.Calibration can be done to compensate for AC load, so its possible to get same power at wheels.Some vehicles come with inbuild calibration to provide same power at wheel even with AC on while some vehicles don't. In most old vehicles I has to switch the AC off to get enough power to accelerate.Max speed will obviously be different for AC on and AC off case.If alternator is running on battery : No effect on acceleration.
What is the difference between speedometer and tachometer?
In general the speedometer and tachometer are used to measure and display speed but to be specific they differ in what they represent ie Speedometer displays the speed of the vehicle whereas tachometer displays the speed of the engine.Speedometer displays the speed in km/hr or miles/hr and it can be analog or digital display where the change in measure is shown when the vehicle is in motion state ( not necessary that the engine is running ) and hence directly related to the speed of the vehicle.Tachometers displays the speed in RPM ( Revolutions Per Minute) which starts displaying the change in measure from the time the vehicle has started ( engine is running ) but the vehicle can remain idle or in motion. Usually vehicle in idle might have an RPM somewhere between 750–1000 RPM and once you accelerate either in idle state or in motion the RPM measure increases and the corresponding measurement is shown and hence directly related to speed of the engine.Hope this helps, good luck!!