Different Type Of Car Exhaust Smoke And Its Causes

Different Type Of Car Exhaust Smoke:Here we will know about different type of car exhaust smoke type. What is exhaust smoke,type of exhaust smoke and its causes.

What Is Exhaust Smoke ?

Exhaust smoke is a way of your car communicating with you to say what is wrong with it. Usually,the smoke that gets emitted from your car is black,white,grey or blue in color. The exhaust smoke gases is normal way to detect symptoms of problem in the vehicle.

Knowing the difference between the smoke that comes from the car exhaust is very helpful. Take note when the smoke appears and its color and report back to your vehicle mechanic. Keeping away from from the problem will shorten the life of the engine and result in unneeded repair bill.

Different Types Of Car Exhaust Smoke And Its Causes

1.White Smoke

Thick white smoke can be caused by engine burning coolant. This can be caused by the coolant leaking into the engine due to leak in the head gasket, damaged cylinder head or cracked engine block.If you see this kind of smoke take your car to the mechanic as soon as possible.

As leaking coolant can lead to overheating of vehicle which could cause damage to engine.White smoke has differing amount of causes and symptoms,which are more common in petrol cars.

Causes For White Smoke In Petrol Cars

  1. Head Gasket Failure-A common issue with car thats maintenance has been neglected or simply the gasket has reached the end of its lifespan.
  2. Problem With Vehicle Turbo-The turbo usully emits white or grey that mostly appear when you accelerate the vehicle.Seals and pump failure are common problem and turbo problem get intensify with vehicle age.
  3. Crack In Engine Block-Not common but cracked engine block will force white smoke from exhaust.

Causes For White Smoke In Diesel Cars

  1. Worn Or Leaking Injector-Fuel injector seals are prone to breaking down which eventually leads to fuel leak.This can cause white or blueish smoke to blow from the exhaust.Inspect engine to find if there are any signs of fuel leaking.
  2. Low Quality Diesel-Poor diesel quality can cause a blueish mix of white smoke to emit from the exhaust system. Its highly recommended to use high quality injector cleaner to treat diesel fuel.
  3. Engine Cylinder Low Compression-Usually cause by piston rings becoming worn out.

2.Black Smoke

Black smoke emitting from car are common in diesel vehicle.The majority of older diesel vehicle will bellow black smoke when accelerated heavily.This result in poor mileage and extra stress on engine components.

Causes For Black Smoke In Petrol Cars

  1. Rich Mixture-A rich fuel or air mixture will cause black smoke under acceleration. This can be result of distributor unit providing too much fuel to the injector or fuel is not getting enough air.
  2. Not Enough Air-A choke air filter or not enough air getting to intake system offset air to fuel ratio.In almost every circumstances,black smoke from petrol car is due to inbalance air fuel ratio.

Causes For Black Smoke In Diesel Cars

  1. Choked Air Filter-With dust particle blocking the air filter,there are chances that adequet amount of air is not reaching the engine cylinder.As result ,more amount of fuel is being burnt this causes black smoke from exhaust.
  2. Faulty Turbocharger-Diesel fuel requires adequate air ratio in order to perform.Poor ratio is usually caused by faulty turbo,dirty air filter and sensor that control air flow.
  3. Defective EGR Valve-EGR reduces the emission of nitrogen oxide by re-circulating engine exhaust gas to internal engine combustion.If EGR valve is damaged,it emits black smoke from exhaust.
  4. Damaged Fuel Injector-If injector don’t close on time or they are clogged. There are chances that more fuel is injected in certain area. In this condition,even the amount of air is insufficent for the combustion of fuel due to clogged injector. This result in carbon formation ,which emitted as black smoke from exhaust system.
  5. Faulty MAF Sensor-A malfunctioning MAF sensor can lead to poor performing engine. MAF sensor determine volume of air entering the engine. Therefore it helps in measuring the amount of fuel to be injected.
  6. Overfuelling-To much diesel pumped from fuel pump.
  7. Poor Diesel Quality-Poor quality of fuel will cause black smoke to come from the exhaust.

3.Blue Smoke

Blue smoke indicates that the car is burning engine oil. This happens when piston ring are worn out and oil is leaking to combustion chamber where is it burned together with the fuel. Burning oil causes rough start because it ruin car spark plugs.

Causes For Blue Smoke

  1. Stuck PCV Valve-Stuck Positive Crankcase Ventilation (PCV Valve) – The function of PCV valve is releasing the pressure into the intake manifold which build up in oil chamber pan. The intake manifold is linked to air filter of the vehicle engine also. When PCV valve get stuck it keep mixing the engine oil with air inside the engine. Combustion of this mixture will cause blue smoke from vehicle exhaust.
  2. Worn Engine – The worn engine is also responsible for blue smoke from exhaust. Each engine has piston which are moving up and down inside the cylinder. Each piston has metal ring around it called piston rings. The function of these pisto rings is to help the piston forming a tight seal againts the cylinder. So if piston rings or cylinder is worn out ,oil from below the piston will come up. These oil then gets mixed with air and fuel and get burned causing blue smoke.
  3. Blown Turbo – Blown turbo is possible reason causing blue smoke in cars that have turbo. Blue smoke will suddenly appear in big cloud if you car turbo is blown. It is either the turbo casing has been damaged or turbo oil seal is broken. In both condition it let oil into the intake of the engine.

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2 thoughts on “Different Type Of Car Exhaust Smoke And Its Causes”

  1. I find it alarming that seeing different smoke colors from your vehicle can signify that their components need servicing! My friend is interested in purchasing a used car this year. Maybe he should try visiting a local auto repair shop whenever these signs appear.

  2. Black smoke coming from our car is something I want to avoid as much as possible. Learning what can cause this is really helpful as I can see some preventive maintenance being extremely important to keep it from making other people uncomfortable. I’ll take your advice and start going to a local auto service that can help with things like air filter cleaning.


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