You may not believe this but the knocking sound you hear coming from your car’s engine could actually be the accessory belt. JTR Repair advises that when this belt gets too loose, it can make knocking noises as it makes contact with the engine. Tightening the belt will alleviate the knocking sound. This being said, let’s talk about the causes of engine knock below. It’s important that you bring your vehicle to our shop as soon as possible if the engine is knocking to avoid further engine damage.
Wrong Fuel Octane Rating
If you have gasoline in the tank that does not have the correct octane rating recommended by your vehicle’s manufacturer, the engine will knock. The reason why is simple: multiple detonations. For example, if your engine requires an octane rating of 91 and you put 89 in it, the 89 fuel will fire more than one time in the cylinders, and this is what makes the knocking noise.
Malfunctioning Knock Sensor
The engine is equipped with a sensor that tells the engine control module if it hears any knocking. This gives the engine control module a chance to try and correct the problem. If the knock sensor is malfunctioning, it may not notify the engine control module that the engine is knocking. Consequently, your engine will continue to knock constantly while it is running.
Fuel Mixture Filled With Air
One thing that the engine control module can correct is a fuel mixture that is filled with air. This is called a lean fuel mixture, and the engine control module can add gasoline to the mix to balance it out. If it fails to do so, the engine will knock for the same reason why it knocks if you don’t have the correct octane in the tank. The lean fuel mixture will fire multiple times
Misfiring Spark Plugs
If you’ve ever dealt with misfiring spark plugs, you know the knocking sound that they make. There are generally two reasons why spark plugs will misfire. The first reason is that the plugs and the wires are worn and need to be replaced. The second reason is that there is a problem with the engine control module that is preventing it from firing the spark plugs correctly.
Worn Rod Bearings
Finally, worn rod bearings are the reason why we said continuing to drive your automobile can damage the engine. The knocking sound that you hear in the engine is the pistons knocking against the cylinder walls. If the rod bearings are worn, they will be unable to move the rods and pistons up and down inside the cylinders evenly.
JTR Repair in Crawfordsville, IN, can help, so call us today.
