What is a Backfire?

Just about everyone has heard of a car backfire before. The backfire is used as an element of comedy in movies and television shows, often providing a thick blanket of black smoke that provides plenty of laughs. Other people have been nearby when a car would backfire, often startling people and animals who may think they have just heard a gunshot. Essentially, the backfire occurs when a buildup of gases within the engine of a running vehicle suddenly ignites and pushes through the exhaust system to create a loud boom. Here is some of the background on how backfiring occurs, and what to do if your vehicle begins to backfire.

Sometimes referred to as afterfire, backfiring can occur when a blockage occurs somewhere within the internal combustion engine of any vehicle. Often, the backfire has an origin in the adjustment of the carburetor. Since the carburetor in older type engines helps to ensure the mixture of gasoline and air is maintained properly, any adjustment that throws off the balance could lead to the collection of gas fumes within the unit. Also, this same sort of condition can take place in the intake manifold of the engine. After some buildup, the result will be a loud bang, often followed by a bellow of smoke out of the tail pipe of the car. The result can be quite embarrassing, not to mention noisy and irritating.

While few newer engines that do not rely on carburetors experience a backfire, it is not completely unheard of. Generally, it is the same basic principle of some sort of imbalance between gas and air consumption that creates the problem. Typically, the modern mechanic can quickly electronically scan the engine and exhaust system of the vehicle and isolate the origin of the problem in no time. In some cases, the repair is relatively inexpensive, and can be conducted without the need to break into the engine. In other instances, the backfire may be a sign of a larger problem that will only get worse with time. If that is the case, the repair work may be quite expensive, as well as time consuming.

The comic value of the backfire will not doubt continue to amuse audiences for many years to come. However, the incidence of backfires in engines today is significantly lower than even twenty years ago. It is very possible that within a generation, the backfire will be a thing of the past, as far as automobiles are concerned.