What Causes the Engine Knocking Sound?

Why do you hear an engine knocking sound in your car? Read on to find out why you hear this sound and what you should do.


Do you hear an odd knocking sound whenever your engine is running? This can happen when your engine has been left idle, ramping up, or simply moving along smoothly. Any of the three could be the case. Engine knock is a common problem in modern vehicles, and while it’s becoming less common, it’s still a difficult problem to cure when it does occur. Excessive wear and even engine failure might result from driving a car with an engine knock.


What is an Engine Knock?

The noise we hear from a vehicle’s engine is the result of many moving parts. It’s time to sit up and listen if you start hearing strange sounds. The valves, or tappets, may be sticking if you hear a quiet tap that increases or decreases with the pressure on the gas pedal.


If you observe a loss in power, the ignition timing is likely wrong. When you start the car, you’ll hear a rattling sound followed by a louder knocking sound that will help you figure out what’s wrong with the ignition timing. Repairing rattling that appears to originate from beneath the engine will take longer.


Most drivers don’t know how to tell the difference between crankshaft (or detonation knocking) and piston ring sounds. A reputable service center should be able to assist you.


Knocking or pinging engines indicate the presence of other issues. Engine repairs will be expensive if the knocking becomes louder and ends with a bang, followed by metallic grinding or screeching. When your engine knocks and your check engine light comes on, it’s a sign you need to do some work or take your car to a mechanic.


READ: How to Increase Your Truck Battery Life


Causes of Engine Knock

Worn bearings

Rod knock is a form of engine noise. The crankshaft is turned by the pistons as they move up and down in the engine, transferring power to the wheels. Rod bearings provide for smooth piston movement, but they can wear out or misalign over time. The pistons will rattle against the crankshaft as the bearings wear down, producing a knocking sound.


This problem could mean that the pistons or crankshaft need new bearings or other maintenance. These parts are deep inside the engine, so fixing them can take a long time.


Bad knock detector

Because the air/fuel ratio, fuel injectors, and timing are all computer regulated, engine knock isn’t a common occurrence in modern cars. There’s even a knock sensor that detects engine knock and informs the engine control unit, allowing it to instantly repair the issue.


As a result, a faulty knock sensor might cause the engine to stall. Checking the knock sensor is an important component of the diagnostic process if you’re driving around in a modern vehicle with an engine knock.


Low octane rating

You may have low octane if you hear an engine knock in your car. This signifies that you’re using the incorrect gasoline in your car. Some cars require high-octane gasoline, which can endure higher compression before igniting.


In other words, engine knocking can occur if you use lower octane fuel in a vehicle that demands higher octane fuel. This is why it’s crucial to consult your vehicle’s owner’s manual to determine what type of gas it needs.


Don’t assume that your vehicle will run on the cheapest gas. You may save money on petrol by using lower octane fuel, but you could end up spending a lot more money if your engine is damaged as a result of using lower octane fuel.


Carbon deposit

Another issue that may arise as a result of hearing an engine pounding is carbon deposits. An engine knocking sound is produced when the fuel pressure varies.


Although gasoline must contain carbon cleaning agents, carbon deposits continue to build. Your cylinders may suffer as a result of this.


To be more exact, it’s when there’s too much carbon in your engine’s cylinders, causing problems with the combustion process. A qualified mechanic will need to clean your cylinders if this is the case.


READ: Reasons Why Your Car Overheats and How to Prevent It


How Much Does it Cost to Fix a Knocking Engine?

A knocking engine can cost anywhere between $2,000 and $3,000 in terms of components and labor. You may have to pay to repair extra parts if the damage is severe. If you put off this repair, the harm will simply become worse (and the expenses will rise).


The cost of fixing an engine rod that keeps banging depends on several things, such as:

  • Has the engine been knocking for a long time?
  • The magnitude of the harm
  • Whether or not the engine can be salvaged
  • Whether the engine is powerful


Even if you’re a seasoned mechanic, repairing a knocking engine is best left to the experts.


Why Does My Car Sound Like a Diesel Engine?

A simple misfire or costly wear and tear of the fast-moving metallic components might generate a strange noise in an automobile engine. This can make your petrol engine make a rattling sound, similar to that of a diesel engine. This is frequently caused by using incorrect or counterfeit motor oil.


Is it Possible to Drive a Car with a Knocking Engine?

You should respond as soon as you hear your engine knocking. The more time you wait, the more likely it is that pistons, connecting rods, bearings, bushings, rings, and other engine components will be damaged. The worst thing that could happen is a hole in the engine block, which would mean the whole engine would have to be replaced.


Valve and tappet knocking may have a temporary impact on your vehicle’s performance and efficiency. Adding a quart of oil now and then can help you avoid having to repair your vehicle for days, if not years. A knocking engine, on the other hand, should be repaired before you go walking.


Wrapping Up

In this article, we have considered different things that are responsible for an engine knocking sound. All of these causes are harmful to the engine. The knocking sound may be solved by changing the oil and spark plugs, using a higher octane fuel, or cleaning the engine. If the noise persists, you should contact your mechanic.

Click Here to Leave a Comment Below 0 comments