The sound of a car backfiring has been compared with a gunshot or firework. It is certainly loud enough to turn heads from quite a distance away. It is not common in newer vehicles equipped with fuel-injection systems, but can still occur under the right conditions.
Basically, a backfire is an explosion inside the exhaust or air intake system of a vehicle rather than in the combustion chamber, where it is supposed to be occurring. This usually occurs when the air to fuel mixture is incorrect and not all of the fuel is burned in the combustion chamber. This means that unburned fuel reaches the exhaust system and may ignite. This produces the well known loud noise and may result in a loss of momentum or power. Let’s take a look at some of the most common causes of a backfiring car.
What causes a car to backfire?
One of the most common causes of a car backfire is poor engine timing. Correct engine timing ensures the spark occurs at the right time and that the fuel burns correctly in the combustion chamber. In modern vehicles this is controlled by a computer system.
Problems with the fuel system such as low fuel pressure, blocked/clogged fuel filter, and an unreliable fuel pump can cause an incorrect air-to-fuel ratio. This may lead to engine trouble, including backfires.
In almost every vehicle manufactured today there is a device called a catalytic converter. This is designed to regulate the emissions by converting harmful substances before they are ejected from the exhaust. However, if this is damaged or removed it can cause backfires in the exhaust system.
There are many other causes of a car backfiring. If your vehicle is having this problem it should be checked by a qualified mechanic as soon as possible.