That Engine Knocking Sound You Hear Could Be the Accessory Belt

Mark’s Auto Service advises that if your engine is making a knocking sound, you may need to have the accessory belt tightened. When the belt is loose, it tends to smack metal parts and make a knocking sound. It’s important to have the belt tightened as soon as possible to avoid engine damage. This being said, this is only one cause of an engine knocking sound. We are going to list the other causes below.

Bad Engine Timing

If the engine timing is off, the engine will knock. It will also sputter and install frequently. Specifically, what is off is the order in which the spark plugs fire. Misfiring plugs can be caused by wear and tear or a malfunctioning engine control module, your automobile’s main computer chip. The module fires the plugs in a specific order for maximum engine efficiency. The plugs may misfire if the module is bad.

Faulty Knock Sensor

You also have a knock sensor in the engine that is manufactured to determine when the engine is knocking. It reports the engine knock to the engine control module so it can make adjustments in the combustion chamber to stop the knocking. If the knock sensor has gone bad, it won’t report anything to the engine control module and the module will not make any necessary adjustments.

Incorrect Octane

Another thing that will make your automobile’s engine knock all the time is if you put the incorrect octane in the tank. In other words, a high-performance BMW cannot run efficiently on gasoline with an octane rating of 87. Use gasoline with the octane rating recommended by your vehicle’s manufacturer. This ensures that the fuel fires correctly and does not cause the engine to knock.

Lean Fuel Mixture

We talked above about the knock sensor and how it warns the engine control module that the engine is knocking. One thing that can make the engine knock is a lean fuel mixture in the combustion chamber. This is a mixture that has more air than necessary and it. Unfortunately, this mixture does not fire correctly in the cylinders and you end up with a knocking engine.

Worn Rod Bearings

Finally, the rod bearings can wear out in older engines and cause the pistons to slam against the cylinder walls. This engine knocking sound is serious because it can damage the cylinders. It can also break a rod, which makes your vehicle’s engine irreparable.

Mark’s Auto Service in Loves Park, IL, or Mark’s Auto Service in Loves Park, Belvidere, Roscoe, and Rockford, IL, would be happy to find and correct the cause of your car’s engine knock. Call us today.

Photo by pomxza from Getty Images via Canva Pro

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