Is My Car’s Engine Really Knocking or Do I Have a Loose Belt?

You are correct if you understand that, sometimes, a loose accessory belt can make it sound as if your car’s engine is knocking. York Tire & Auto Service can tighten the accessory belt if that is the cause of the noise. If it isn’t, your engine is knocking, which means you have problems with the detonation in the cylinders or worn rod bearings. Let’s talk more about these problems below.

Excess Air in the Cylinders

Too much air in each cylinder is called a lean fuel mixture. In order to get optimal detonation in each cylinder, which means you only end up with one fireball, you need to have a balance of air and fuel. Excess air will cause multiple fireballs to bang against each other. This is the knocking sound that you hear when you are driving your automobile.

Malfunctioning Knock Sensor

Your engine is equipped with a knock sensor that is supposed to detect the sound that the multiple fireballs make. The sensor then alerts the main computer chip, the engine control module, that the engine is knocking. In the case of the lean fuel mixture, the computer chip would add more fuel to each cylinder to balance the mixture out. This being said, a malfunctioning knock sensor may be unable to alert the engine control module of the sound.

Misfiring Spark Plugs

Another thing that will cause multiple detonations in the cylinders is misfiring spark plugs. If the engine control module is malfunctioning, it may not fire the spark plugs in the correct order. Consequently, they will misfire. They will also misfire if they are old.

Wrong Octane in the Tank

Your engine will also not constantly if you put the wrong octane in the fuel tank. For example, you cannot use fuel with an octane rating of 89 if your engine requires an octane rating of 91. Anything lower than 91 will make the engine knock constantly.

Worn Out Rod Bearings

Finally, there is another type of engine knock that is called rod knock. This knock is not caused by faulty detonation. Rather, what makes the knocking noise that is coming from your engine is pistons crashing against the cylinder walls. This happens when the rod bearings have worn out and can no longer move the rods up and down inside the cylinders evenly.

Call York Tire & Auto Service in Red Lion, PA, today to schedule a service visit if your engine is knocking all the time.

Photo by Shutter2u from getty images via Canva Pro

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