What does knocking mean in a car

This is especially true of engine knocking noises in your vehicle. When you hear an engine knocking noise, it could for different reasons that require minimal work to labor-intensive work, which is why it's important to be aware of what causes engine knocking noises.

You might think a worse feeling is not knowing what that knocking sound is in your engine. You don't know how much it's going to cost or if you'll have to replace your engine.

This is why it's essential to know what engine knocking is and what can cause this sound. If you have no idea what an engine knocking sound is, then reading about it in this post can offer some insight into what this means for your vehicle and what you can do about it. Here's everything you need to know about engine knocking and why you should never ignore it. Having an understanding of engine knocking can provide some valuable information about your car about what you can possibly do about it if it does happen.

You want to catch these problems immediately before you find yourself buying new or going without a car. If you hear an engine knock in your vehicle, it could mean you have low octane. This essentially means that you're putting in the wrong gasoline in your vehicle. Some vehicles require high octane fuel, which means it can withstand more compression before igniting. In essence, this means that if you put lower octane fuel in your vehicle and it requires higher octane gasoline, you could be damaging your vehicle.

Therefore, if you put in lower octane fuel and your car requires higher octane fuel, it can lead to engine knocking. This is why it's important to look at your vehicle's handbook and see what kind of gasoline it requires.

Don't assume your vehicle takes the cheapest gasoline. You may save some money on gas by opting for lower octane gas, but in the end, you may be spending big when you find there's damage to your engine because you continued to put lower octane fuel in your vehicle. Having a bad knock sensor is almost a best-case scenario if you hear an engine knocking sound. In many modern vehicles, there's an automatic sensor to detect engine knocks.

The sensor detects if everything is running smoothly in the ratio and injectors. However, these sensors can be faulty and can lead to an engine knocking sound. In addition to knowing what to do if you hear a knocking sound in your engine, you can also find more about what maintenance should be done to your car in our blog. Being aware of what maintenance to do on your vehicle can help you potentially avoid an engine knock sound.

You might also find that your engine knocking sound is from a rod knock. The rod bearings allow for smooth piston movement. If any spark plugs other than what is recommended by the manufacturer is used, it can cause the knocking sound you hear.

The spark plug has a certain heat range, which means it withdraws heat from the combustion chamber. Using the wrong part can prevent it from working correctly. It's also common for engine knocking to occur when the spark plug gap is not correctly set.

The spark plug gap is the place where the spark plug ignites the air-fuel mixture that helps power the car. Too narrow of a gap creates a spark too weak to perform this task, and too wide a gap might stop a spark from firing at all, or to only misfire rapidly.

Resolving these types of engine knocking problems is usually rather simple and something most car owners can do themselves. In other instances, it might be prudent to contact a professional technician to correctly diagnose the source of the knocking and recommend the right repairs.

The most popular service booked by readers of this article is Noise from engine or exhaust Inspection. Our certified mobile mechanics perform over services, including diagnostics, brakes, oil changes, scheduled mileage maintenances, and will come to you with all necessary parts and tools.

Our certified mobile mechanics make house calls in over 2, U. Fast, free online quotes for your car repair. Noise from engine or exhaust Inspection Cost. Service Location. What is Engine Knocking? Fuel Has a Low Octane Rating If you put in fuel with an octane rating too low for your vehicle, it can create a knock.

Carbon Deposits Restrict the Efficient Burning of Fuel Fuels for vehicles are required to have a carbon cleaning detergent, but they may not prevent carbon deposits from forming. Incorrect Spark Plugs or Wrong Spark Plug Gap If any spark plugs other than what is recommended by the manufacturer is used, it can cause the knocking sound you hear. Next Step Schedule Noise from engine or exhaust Inspection The most popular service booked by readers of this article is Noise from engine or exhaust Inspection.

Carbon Buildup. Home Noise from engine or exhaust Inspection. The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details. Excellent Auto Repair Ratings. YourMechanic Auto Repair. Related Articles. How Does a Distributor Work? What Is Engine Displacement?

Experienced Mechanic? Recent Noise from engine or exhaust Inspection reviews. Excellent Rating. Rating Summary. Andrew 11 years of experience. Damage to the following parts could cause serious engine issues:. Causes light knocking and is best fixed by performing a cylinder balance test to identify ailing connecting rods. Causes metallic-sounding double knock and is fixed by replacing worn bushing or tightening the piston pin.

Causes loud knock when the engine is under load and can be fixed by replacing rod or thrust bearings. Sales : Live chat.

Types of engine knocks and noises Single loud knock This kind of engine knock occurs once and feels as if something just blew up under the hood. Detonation knock This type of knock begins with a metallic ping which is then followed by a detonating sound in the engine.

Light pounding knock This knock occurs when the engine is at an even rpm, i. Slapping knock With this knock, you will hear a hollow, muffled, or slapping sound inside the combustion chamber of the engine. Low-octane fuel One thing you must always be cautious about is the quality of fuel that you feed your engine.

Carbon deposits In Texas, fuel distributors must include carbon cleaning detergents in gasoline to dissolve deposits that potentially clog up engine cylinders. Worn engine components An engine with many years of service will undoubtedly be prone to knocking from worn components. Damage to the following parts could cause serious engine issues: Crankpin Causes light knocking and is best fixed by performing a cylinder balance test to identify ailing connecting rods.

Piston Causes metallic-sounding double knock and is fixed by replacing worn bushing or tightening the piston pin. Crankshaft Causes loud knock when the engine is under load and can be fixed by replacing rod or thrust bearings.

Implement these practical solutions for engine knocking Use high-octane fuel or add octane boosters to low-octane fuels. Use engine cleaning additives to minimize deposit buildups Avoid missing regular checkups as advised by the manufacturer If your engine knocking is persistent or is too expensive to fix, replace it with a new one or even consider purchasing another clean car at an unbeatable price.