Exhaust Smoke: What is my smoke color telling me?

Unusual smoke from your car’s tailpipe isn’t great news and different colours of smoke depict a different diagnosis. In any case, if you notice persistent, thick, funky looking smoke out of the tailpipe, stop driving the vehicle and call a mechanic.

Think of your car as a patient. Unlike a regular patient coughing, your car coughs up smoke out of its tailpipe. Although most of the time you need professional help to solve the problem, there are a few initial diagnostic tools which you possess too: sight, smell, hearing and feel.

Let’s look at the warning signs that can indicate trouble based on the colour of the exhaust smoke.

White or Grey Smoke: 

  • You will notice massive clouds of white smoke. 

  • Caused by:

  1. Coolant is being burnt up within the engine and expelled through the tailpipe

  2. There is a spill or leak somewhere in the engine block, head gasket and cylinder head.

  3. Risk: It puts your vehicle at risk of overheating

  • Note: Not to be confused with the normal white vapor that you see the first time you start your car, especially if it’s a cold day, and it’s fairly normal. 

Blue Smoke: 

  • Blue smoke indicates there’s likely an oil leak and your engine is burning oil.

  • Caused by 

  1. Leaking valve seals(due to a clearance problem between the valve and the valve guide in the cylinder head)

  2. Worn or damaged piston rings.

  3. Worn cylinder walls.

  4. Depletion in lubrication around the moving parts of the engine.

  • Risk: 

  1. Increase the wear and tear of those parts causing them to quickly need to be replaced or worse.

  2. Increases chances of a seized engine that will need to be replaced or rebuilt.

  3. Poor mileage, acceleration, starting and rough idle

 Black Smoke: 

  • Think black exhaust smoke means the vehicle is burning too much fuel

  • Causes 

  1. A clogged air filter

  2. Malfunctioning fuel injection system

  3. A blocked manifold

  4. Stuck fuel pressure regulator 

  5. Restriction in the fuel combustion pipe. 

  • Risk: 

  1. Lowers your fuel-efficiency of your engine and poor performance of the vehicle

  2. Engine running rough, along with poor mileage.

  • Note:This usually happens with relatively older cars and it is very important to get the leaks checked from a good mechanic.


With all the colors and all the scenarios, something is damaged when it shouldn’t be. 

  • If your exhaust is sending up smoke signals, rush to an autocare centre and visit a knowledgeable expert.

  • Help your technician address the issue by taking note of when the colored smoke occurs.

  • Bring your vehicle in for a courtesy inspection as soon as possible.

For reliable, good quality services, be sure to visit your nearest Redfox garage in Abudhabi or Ras Al Khaimah. With the latest diagnostic equipment and advanced technology, your car is in experienced hands. We undertake preventive maintenance to protect your car from all kinds of damages like oil leaks, broken engine parts, a clogged filter, or something else.. To book, visit our website, or contact us via Instagram/Facebook at @redfox.ae.