Black engine smoke
Black smoke leaving your engine is often a sign that too much fuel is being burned. It could also be caused by a clogged air filter. If you catch either fault early, they are usually easy to fix.
1. Faulty Fuel Injector
Fuel injectors deliver petrol or diesel into the engine as a high-pressure mist. They can become clogged up with dirt or low-quality fuel, or leak because of wear and tear to the seals. Both the seals and injector itself can be replaced by a qualified mechanic.
2. Damaged fuel pressure regulator
Just as the name suggests, this part of the fuelling system regulates the pressure of petrol and diesel being fed to your car. The part can be found either outside or inside the fuel tank and this will affect the cost of a replacement. You should check with your local garage if the fuel pump needs to be replaced at the same time.
3. Dysfunctional carburettor
Older cars use a carburettor to mix air and fuel. When the part fails and delivers too much petrol or diesel to the engine you’ll notice dark smoke. It’s important to get the problem checked as soon as possible by a professional, as your car will be burning too much fuel and therefore producing excessive emissions.
4. Blocked inlet manifold
The inlet manifold supplies a mixture of fuel and air to cylinders in the engine. A blocked inlet manifold will only allow a limited amount of the mixture to the combustion system, which can cause your engine to cough up a cloud of dirty smoke. Although this part can be cleaned at home, it’s best to enlist the help of a professional if you’re not sure what you’re doing.
5. Ignition timing is off
In order to burn properly, fuel must be ignited at the right time during the combustion cycle. When your ignition timing is off, your engine will burn more fuel than necessary and in extreme cases pump out clouds of black smoke. If you think your car is using excessive fuel you should have the engine looked at by a trusted mechanic.
5. Ignition timing is off
Your air filter prevents unwanted debris from being sucked into your car’s engine. Contaminants collect in the filter over time and prevent the filter from working properly. In some cases the filter can also become damaged. If debris reaches the combustion engine it can be burned along with fuel and escape as black smoke. Thankfully, a filter replacement is a straightforward job which you can do yourself, or get a garage to do quickly for you.