Spitting And Sputtering? Misfires And Their Causes

Misfires are one of the most annoying and difficult-to-diagnose problems that can afflict a vehicle. From the perspective of the driver, a misfire often feels like the engine is stuttering or hesitating, and a car that is misfiring consistently will usually have major drivability issues. Although a single misfire is usually not enough to trigger your car's check engine light, repeated misfires will cause the computer to store a confirmed code and turn the light on. Of course, just knowing that you have a misfire isn't very helpful, but with a little bit of knowledge, it may help you to track down the underlying cause.

What's Actually Going On?

It's usually fairly obvious when your engine misfires, but what's actually happening inside of your engine? As a general rule, misfires are caused when one or more cylinders are unable to complete a full combustion cycle. This can happen for a wide variety of reasons, and the problem may actually lie at almost any point in the combustion cycle. If the misfire is happening only infrequently, then this creates a sensation that the car is hesitating or on the verge of stalling. A consistent misfire, on the other hand, may simply make it feel as though your car suddenly has no power.

The Basics of Misfire Diagnosis

Although determining the ultimate cause of a misfire can be tricky and is best left to professional technicians, it's usually fairly straightforward to understand the immediate cause. All engines require fuel, a spark, and compression to function properly. Without fuel or a spark to ignite it, your engine cannot produce power. Unfortunately, determining that the problem lies with one of these two requirements is only the beginning. There are a variety of reasons why your engine may be starved of fuel or why a spark plug would fail to ignite.

In some cases, an engine misfire may indicate deeper engine trouble. If your car's timing is incorrect, for example, then it is likely that one or more cylinders will repeatedly misfire. Vacuum leaks can also cause serious misfire issues. This is due to unmetered air entering the combustion chamber, creating an imbalance in the fuel to air ratio and ultimately creating a lean condition. In a worst-case scenario, a misfire might be the result of serious mechanical problems, including everything from damaged valves to leaky piston rings.

Dealing with a Misfire

If you suspect that your car is misfiring, then one of the best things you can do is to read the pending codes. These are codes that your car's computer will store without triggering a check engine light. Most auto parts stores will read these codes for free, and code reader tools that pair with smartphones can usually be purchased for less than $20. Pending misfire codes can alert you to a brewing problem before your check engine light ever illuminates.

If you discover that one or more cylinders are misfiring, you should plan to have your car checked by a mechanic as soon as possible. While misfires often result from relatively minor problems, it is nevertheless important to deal with them early. For more information, utilize a resource like Powers Car Care Centers.