Exhaust System and Issues


What is an exhaust system and why is it important?

There must have been times when a car whizzed past you and you turned around to find out which one it is because you liked how it sounded. For all the fans of vehicular action movies out there, they must have a lot of favourite cars on the basis of sound alone. But why do some cars sound so good than others? The nice sound is as much a doing of engine as it is of an extension system. This extension system is called Exhaust system. Its purpose is not just make a car sound amazing but also take out the exhaust gases out of engine (created by combustion of fuel). These gases are routed through exhaust manifold to a turbocharger (if present), a catalytic converter (pollution control norms) and the silencer/muffler to finally in the atmosphere. Since the exhaust system is the only way exhaust gases can escape your car’s engine, it needs to work in top condition. IF these gases do not exit through eexhaust system, not only will your vehicle’s performance and fuel economy go own, it will also pose a health risk to you. If these gases find their way to the cabin, they pose a serious health risk to you.

What are the signs of exhaust issues?

  • Decreased fuel efficiencyIf you notice a drop in your car’s fuel economy, it may be due to an exhaust leak. The exhaust fumes are not being transported properly and your engine is operating at a higher temperature.
  • VibrationsPeculiar vibrations from the gas pedal or steering wheel are certain symptoms of exhaust leak. If the leak is big, the whole car may shake too.
  • Increased Engine NoiseSince exhaust system keeps engine noise down, if you hear your engine rumble loudly, it probably means a leak.
  • Rattling noise under the carIt may mean that your exhaust system is misaligned. Loud metallic vibration could also imply that a clamp or pipe has become loose or something is touching the exhaust pipe.
  • Sudden loud noisesThis may be caused by a broken silencer or exhaust pipe. If you also observe a decline in performance, then the issue might be a broken catalytic converter or cracked exhaust manifold. If the check engine light is on or there are smells from the engine compartment, these too may signify a broken exhaust manifold.
  • Signs of a broken silencer or pipeIf you hear loud or excessive exhaust noise, or there is exhaust smell inside your car or the silencer / pipe is dragging beneath your car.
  • Importance of Exhaust Gas Recirculation / EGR valve → It diminishes the emissions from the car’s exhaust. The valve may need to be replaced if check engine light is on, possible loss of power, or your vehicle doesn’t run smoothly.

Also perform visual checks regularly to spot rusts, corrosions or cracks in the pipes or any holes around the seams and joins for early remedy.

What problems does the color of exhaust smoke indicate?

Smoke is not the only issue you face when it comes to exhaust system. The problem you face really is the kind of smoke that comes out as that will tell you what kind of trouble is actually brewing the engine. Consider the following seriously:

  • Black smokeA little black smoke when your car is just starting, is often usual, but if it continues, then the reason maybe a clogged or dirty air filter. If the problem persists after replacing the filter, then the causes may be bad fuel pressure regulator or leaky/clogged fuel injectors.
  • White smokeIf emission of such smoke continues well after starting the car, it maybe because your engine is burning coolant that has leaked into the combustion chamber. Issues maybe, blown head gasket, damaged cylinder head or cracked engine block.
  • Blue or grey smokeThis indicates that your car is burning oil which has leaked into the combustion chamber of your car’s engine. The culprit is commonly a malfunctioning valve stem seal and at times, failed piston rings.


Exhaust issues may lead to low performance of engine, emission of noxious fumes inside the car and health or safety hazards. So watch out for any symptoms that we have listed above and get the exhaust system of your car inspected at the earliest if you happen to notice any of the issues mentioned earlier. We at CarDekho would be happy to help you get resolved any problem in your car’s exhaust system. You just have to log on to services.cardekho.com.