Common Reasons Why Your Car Might Rough Idle

27 October 2018
 Categories: , Blog


Have you ever been stuck at a light and your car began to jerk aggressively? If so, you were likely experiencing a period of rough idling. Several things can cause a car to perform in this manner, but no matter the source, it's not an issue that is normal, and therefore, is not one you should ignore. Discover some common reasons why a vehicle might perform in this manner.

Spark Plug

Spark plugs work just as their name suggests—they spark. The spark causes your vehicle to burn fuel and, in essence, run. When the spark plugs are damaged, the spark isn't delivered, and as a result, not enough fuel is provided to the engine. 

The poor delivery, in turn, causes the engine to rough idle as it works hard to start. Replacing the spark plug will typically resolve the problem. However, you will need to check the spark plug wires as well, as they can sometimes be the problem.

Fuel Filter

Dirt, dust, and sediment commonly collect at the base of a gas tank. The fuel filter is designed to prevent this debris from making its way into the engine compartment. 

However, when the filter is aged, too much debris can collect on its screen, which can prevent it from adequately trapping the debris. This also restricts the flow of fuel to the engine, which will also cause it to rough idle. The fuel filter should be changed routinely to avoid this problem. A dirty fuel filter can also reduce your miles per gallon rating and damage your engine.

Fuel Injector

In addition to the filter, the fuel injector is also responsible for delivering fuel to the engine. The injector works much like a pump, in that it forces the fuel into the engine. However, when the injector is not working correctly, the pumping system won't work. 

In some instances, it's not that the injector is not working, but that it is also full of debris, similar to the fuel filter. Many professionals recommend that owners use fuel injectors periodically to keep the injector line clean and to ensure proper fuel delivery. An auto technician will be able to tell you which blend of injector cleaner to use and how often to perform this step.

If your car is rough idling, take your vehicle to a repair technician. At an auto repair shop, such as Car and Truck Services Inc., a technician will be able to diagnose and repair your vehicle for you.