Know What the Smoke from Your Car’s Exhaust Pipe is Trying to Tell


Unlike the cars from the 70s, the exhaust system implemented inside your car is efficient enough to avoid any smoky exhaust. The proper use of elements like catalytic converter, muffler and lambda sensors, reduce smoke to the extent where it is not even visible with naked eyes. This means, if your car is sputtering smoke, there’s definitely something wrong and needs consideration. Exhaust smoke could vary in color from white, gray, blue to black. The type of smoke color can help to identify what’s wrong with your car. Let’s see, what different colored smoke from your car’s exhaust means.

Thick White Smoke

A thick white smoke from the exhaust is a common indication of burning of coolant or water during the combustion process. The mixing of coolant or water with the fuel occurs usually due to a blown gasket or if a crack is formed on the cylinder head. Since, fuel becomes infected, the engine will run rough and at the same time, there are chances of engine overheating as coolant level gets reduced. A thick white smoke will have usually a sweet smell too.

Thin White Smoke

Thin white smoke appears in the exhaust usually during the initial cold start of the engine. This happens mainly due to the condensation process in the exhaust, which occurs as the muffler and the tail pipe takes time to warm up after cold starting the engine. You might also notice condensation dripping from the muffler’s drain hole. This type of smoke will disappear once the elements of the exhaust system reach a required temperature.

Blue Smoke

This type of smoke is commonly seen in the exhaust due to mixing of oil with the fuel. This usually happens due to broken piston rings or valve guides. If the amount of oil keeps on increasing, the spark plugs will develop deposits, causing them to reduce the spark intensity and ultimately reduce the engine efficiency. The engine in such circumstances runs rough and requires immediate attention, as the piston may seize without proper lubrication.

Black Smoke

If your car is throwing black smoke from the exhaust, you might need to consider it seriously, as this may indicate that the engine is running rich (i.e. more fuel than required). However, you can easily recover from your car from this problem. There are few common elements that should be inspected, such as, fuel line which may have clogged, a stuck fuel pressure regulator or fuel injectors that may be leaking.

Gray Smoke

At cruising speeds, the engine will develop carbon deposits inside the combustion chamber to some extent. When the accelerator is pressed hard for instant speed, these carbon deposits burn and cause the smoke to turn gray.

  • Steven jones

    Car or vehicle exhaust smoke do tell us many things. If your engine isn't clear then the only way to know about it is by the exhaust smoke.