Consider Changing Your Oil Before a Summer Road Trip

Why Are There Knocking Sounds Coming from My Engine?

It’s never normal to hear your engine knock. In fact, if you are constantly hearing your engine knocking, it could indicate a serious problem. The most common cause of engine knock is a detonation issue under the hood. In other words, each cylinder has multiple detonations rather than just one, and these small explosions can produce this knocking sound you are hearing. Here are five of the most common causes of engine knocking. Some are easier to fix than others, but one thing is for sure: if you hear knocking in your engine, bring your vehicle to an auto repair shop right away. 

Poor Engine Timing

The spark plugs are what cause the small explosions in the cylinders. Engine detonation is caused by these plugs igniting the air and fuel in the cylinders. If your spark plugs are worn or your vehicle’s engine control module is malfunctioning, the plugs may not fire when they should, resulting in multiple detonations in the cylinders. The knocking sound is caused by these detonations.

Faulty Sensor

Engine knock is detected by a sensor in your car, truck, or utility vehicle. It notifies the engine control module when it detects the knocking sound so it can make adjustments in the combustion chamber to keep the engine from knocking. If the knock sensor fails, it will not alert the module to any issues, and this can cause your engine to consistently knock. 

Fuel Mixture

Why Are There Knocking Sounds Coming from My Engine?Faulty mass airflow and oxygen sensors can have a direct impact on the fuel mixture in the combustion chamber, resulting in a lean fuel mixture. When this happens, the cylinder firing sequence is thrown off, resulting in multiple detonations in each cylinder. This, too, produces the irritating knocking sound that you hear while driving your car.

Low-Octane Fuel

Low-octane fuel is another issue that can cause constant knocking. If you drive a high-performance vehicle and fill the tank with 87 octane, your engine will knock. This is because your vehicle requires higher-octane, faster-burning fuel. Low-octane fuel burns more slowly, which can cause engine knocking in some vehicles.

Worn Rod Bearings

Finally, constant knocking could indicate a serious engine problem. It’s possible that the rod bearings that move the rods up and down are worn. The rods crush the pistons into the cylinder walls when these bearings wear out. This could be another reason for the knocking you are hearing from your engine. 

If you are experiencing any of these issues and your engine is particularly noisy, you should have it checked out at a trusted auto repair shop by a qualified mechanic. There are many skilled mechanics here in San Diego, and you need to pick one that is able to deliver the quality of work you need. 

Engine Repair San Diego

You always need a reliable mechanic. Automobile Repair Shop San Diego has been providing high-quality auto repair in San Diego for many years. To learn more about how we can assist you with your auto maintenance, call (619) 330-0862 right now.