Blogs

What Is That Knocking Sound Coming From My Engine?

Most likely, the knocking sound that you hear coming from your engine is multiple detonations in the cylinders. The spark plugs ignite air and fuel in each cylinder so they will detonate one time. If the air and fuel detonate multiple times, your engine will make a knocking sound. There are many things that can cause detonation knocking. CAR FIX in Cookeville is going to list the common causes of detonation knock below. We will also include another reason why your engine knocks all the time.

Bad Engine Timing

If the spark plugs are worn or there is a problem with the engine control module, the spark plugs may misfire and this will cause multiple detonations in the cylinders. Replacing worn spark plugs will resolve the problem. This being said, the issue might also be caused by a faulty engine control module that is firing the spark plugs multiple times or out of sequence.

Faulty Knock Sensor

Your engine has a sensor to detect when it starts to knock. This sensor notifies the engine control module that the engine is knocking so it can make adjustments to stop the knocking. Unfortunately, this sensor can go bad. When this happens, your engine may not because the sensor is unable to report the problem to the engine control module.

Lean Fuel Mixture

Any time there is too much air in the combustion chamber, your vehicle has a lean fuel mixture. This means that there isn’t enough fuel in each cylinder to fire up immediately when the spark plugs send a spark into the cylinder. Rather, you end up with multiple detonations that make your engine knock. Things that can cause a lean fuel mixture include a clogged fuel filter or fuel injectors.

Low-Octane Fuel

It’s important to make sure that you always put the right octane in your gas tank. If you drive a high-performance automobile and use low-octane fuel, your engine is going to knock because the gasoline does not fire up quickly enough for a single detonation. Rather, it will detonate multiple times in the cylinders.

Worn Rod Bearings

Finally, this cause of engine knock is not related to detonation. Rather, the sound that you hear is the pistons banging against the cylinders. Rods move the pistons up and down inside the cylinders and rod bearings help the rods with this movement. If the bearings are worn, the rods may bang the pistons against the cylinder walls.

Call CAR FIX in Cookeville, TN, today if your engine is knocking all the time. We can find the problem and fix it.

Photo by AppleEyesStudio from Getty Images via Canva Pro