What are the Causes of Engine Knocking, and How to Fix It?

knocking sound in car

There can be instances in your driving experience when you hear a pinging sound from your engine. Don’t freak out if you hear an engine knocking sounds. There are several potential causes of the problem, and the majority of them are simple to resolve. It is in your best interest to take quick action to save yourself from expensive repairs. We’ll talk about the reasons for engine knocking in the following blog, along with some potential fixes. However, not all engine pinging sounds are equal, but it is necessary to treat them equally and attentively. 

What Leads to Engine Knocking?

The piston and crankshaft work in synchronization to provide optimum power. The piston draws fuel and air into the cylinder when it falls down. Whereas when the piston goes up, it compresses fuel and air. With continuous ascending and descending, there is a generation of optimum power.

In the functioning of the engine, each spark plug is activated when the crankshaft reaches optimum rotation. Your car’s timing controls how hard each cylinder is pushing the crankshaft and maintains them all moving in the same direction. So, when the fuel in the cylinder ignites prematurely, it generates an engine-knocking sound.

If, before the piston reaches the center, there is ignition, then it affects the smooth rotation.  Due to misfiring, the piston applies a backward force on the crankshaft. It causes the engine to produce a pinging sound. The surface of the piston, the cylinder walls, or the crankshaft bearings can all be harmed by knocking.

Cause of Engine Knocking Sound in Your Car

Cause of engine knocking sound in a car

Let’s discuss what the engine-knocking causes are.

Defective Spark Plug

If you hear an engine knocking sound, the very first thing you should consider inspecting is the spark plug. The fuel-air mixture ignites with the help of an ignition spark. However, if your spark plugs are not in good condition, they probably have build-up fuel stuck to it. Also, there could be a reason that your spark plug isn’t producing any spark. Also, if you don’t replace the spark plug with the right one, your car engine will run rough.

The best way to resolve the problem is to choose the spark plug with the correct specifications according to your repair manual.

Bad Fuel Injector

Another reason for your car engine producing a knocking sound is the bad fuel injector. A defective fuel injector causes a poor mixture of air and fuel to enter the cylinder. Due to poor mixture, the temperature of the combustion chamber rises and creates uneven pressure causing ignition untimely.

Replace your bad fuel injector to get rid of the knocking sound in the car.

Low-Quality Fuel

In the market, there is a variety of fuels. They are differentiated in terms of octane level. If you are using fuel of lower octane level, then it is a low-quality fuel. Poor quality of fuel sticks to the crankshafts and combustion chambers and affects the functioning of the engine. With low-octane fuel, you will receive a disproportionate mixture causing the engine to knock.

Low-quality fuel can save you money, but it can degrade the quality of the engine. It is a best practice to give your car optimum octane level fuel to avoid any damage and fix engine knock.

Faulty Bearings

The rod bearing causes the smooth movement of the piston. Their bearings are also in the fan belt. So, when any bearing in the engine is worn out, it will produce a pinging sound. The piston and crankshaft will rattle. Moreover, the faulty bearing will not hold up the engine in its place. Also, pulleys and belts will work roughly.

All of these will cause the engine to produce a knocking sound. Fixing the bearing will fix the rod-knocking problem. However, it is a time-consuming repair as the bearing is located at different positions in the engine and requires a skilled mechanic to handle it.

Damaged Piston

A damaged piston should also be on your checklist if you are hearing a knocking sound from your car engine. The piston is responsible for compressing the right air and fuel mixture. Thus, when a car piston is damaged, it will not work according to its engineering process and will produce a pinging sound.

If the piston is severely damaged, it will ultimately damage the engine. Your car engine won’t work efficiently. The only option left is to buy a new engine. You can save money if you decide to go for used LS engines for sale.

Malfunctioning Knock Sensor

A knock sensor in modern vehicles can detect engine knocking. It alerts the engine control unit and resolves it quickly. If you fill your tank with fuel with a low octane rating, the engine may need a longer delayed ignition timing to function without engine knock.

Therefore, the purpose of the engine knock sensors is to keep an eye out for any knocks and, if they do, to instruct the engine to delay the ignition even more to avoid engine damage.

However, the engine knock sensor may transmit misleading signals to the engine control unit if it has malfunctioned. It will cause a false motor knocking sound. It can affect a vehicle’s performance and fuel economy.

Always take your car to a qualified mechanic if you think a sensor is at the back of all the problems.

Frequently Asked Questions

If my engine is knocking, do I need a new one?

Having a fully functional engine is necessary for performance and fuel savings. When an engine is ticking or knocking, repairing and replacing the faulty component is the first option. However, if the damage is beyond repair, you must buy a new one.

An faulty spark plugs result in an engine tapping noise?

When the spark plugs are not accurately igniting air and fuel mixture in the combustion chamber will result in faulty car engine detonation.

Will thicker oil stop the engine clanking noise?

Thicker oil won’t stop the engine knock. It is just a temporary way to avoid the car knocking noise. The knock sensor will continue to detect any tapping noise from the engine. If you have rod knocking or a bad fuel injector, thicker oil won’t fix anything.

Leave a Reply

Your email address will not be published. Required fields are marked *

Request a Quote For

Sirdebar Contact Us

Request a Callback

Contact Us

This will close in 0 seconds

Your Request Has Been Submitted
The Next Step is To Contact US

+1 (252)-503-4920

This will close in 20 seconds