Engine Knock On Startup Then Goes Away: Why Here!

If you’re experiencing an engine knock on startup then goes away after a few moments, you’re not alone. This common issue can be alarming for car owners, but it’s essential to understand what’s causing it and how to address it. 

Engine knock, also known as engine pinging, is a sound that occurs when the air-fuel mixture in your engine’s combustion chamber detonates in more than one place simultaneously. 

Several factors, including low-quality fuel, incorrect ignition timing, or worn engine components, can cause this. 

While it may not always indicate a severe problem, it’s always best to have it checked out by a mechanic to ensure the longevity and reliability of your vehicle.

What Is Engine Knocking

What Is Engine Knocking?

Engine Knock is a common name for sounds that originate from engine operation problems. This phenomenon occurs quite commonly on systems that are too old or are suffering from serious errors.

Often, uneven fuel detonation is the leading cause of Engine Knock. Because if not burning at the same time, the oil or gasoline will tend to explode alternately until the air is consumed. This process will still generate forces, but these effects are too small to be necessary.

So instead of pushing pistons and transmitting power to the wheel axles, the fuel will make annoying sounds when the impulse collides with metal parts only. With the proper treatment, you will avoid unnecessarily using a lot of energy.

What Does An Engine Knock Sound Like?

Pinging is the characteristic sound you will hear if the Engine Knock phenomenon occurs. Different from noises like rubbing noise when turning at slow speeds, you will listen to the ping sound quite clearly.

Depending on the engine’s condition and structure, the Engine Knock’s size will change. But I’m sure you’ll soon find out where the problem is because the discomfort caused by pinging is extremely noticeable no matter the intensity.

Engine Knock On Startup Then Goes Away

Why Does Engine Knock On Startup Then Goes Away? How To Fix It?

The leading cause of engine knock on startup and then going away is often due to hygiene-related problems such as carbon accumulation.

In addition, the parts that stick together or are too worn can also cause the vehicle to emit these annoying sounds.

Of course, many other factors could create the audio problems I’m talking about. But compared to the above failures, the frequency of occurrence of these causes is much less.

Here are some of the most common causes of annoying pinging sounds I’ve found and put together for you. The incidence of these errors is relatively high on most plots. So you’ll likely run into problems while learning about what’s happening with the vehicle.

Bearing wear

Bearings are an essential mechanism in engine operation. It is not too difficult to understand when this part will quickly wear out after a specific time.

The result of this process is unnecessary clearances and causes the crankshaft to beat continuously with the bearing, causing loud engine noise on startup.

When the vehicle is operating, the system’s temperature will increase, which will cause the metal parts to expand gradually. Bearings are no exception, of course.

But that’s also why the gap between this detail and the crankshaft is no longer there. The sound of metal banging also disappeared from there. But you will hear this sound again if you let the engine cool down.

Wear parts

As engine parts wear out, most of these parts will create unnecessary gaps or crack and come apart from their original positions. The above processes will create Engine Knock.

In particular, the intensity of the sound produced will be even greater if the problem comes from essential mechanisms such as pumps, generators, or exhaust pipes.

To put an end to this situation altogether, the only measure that we can take is to conduct an investigation into the cause and completely replace the outdated part.

Fuel problem

The Engine Knock phenomenon is very likely to occur if we use fuels that do not have enough stable combustion or create an unstable energy source. 

Because this is the premise for the combustion process to occur more unevenly. That makes the impulse generated just enough to make a noise instead of pushing the piston away.

It is easy for us to deal with fuel-related problems. In addition to draining the unsuitable amount of liquid, you only need to clean and refuel. Remember to learn more about how to test for bad gasoline to avoid choosing the wrong product.

Piston Slap

Piston Slap is a unique phenomenon that usually only occurs in vehicles that have experienced a too long operating time without receiving proper care. In addition, some models with errors during assembly and manufacturing will also encounter this situation.

The cause comes from the piston no longer moving in the correct up-and-down route. Instead, the unit will operate chaotically in both straight and diagonal lines. This process creates a knock and produces a sound we call engine knock.

If you encounter a Piston Slap, taking your vehicle to a repair shop for help is best. The problems with this mechanism are often beyond our ability to self-repair at home.

Oil Drain Back

The check valve is a mechanism that helps prevent oil from flowing back into the system. This detail will not cause unpleasant sounds. Instead, improperly closing or deliberately replacing genuine parts with cheap filters are the leading causes of pinging.

This unit will remain active and make a sound until the oil from the tank contained get to all the mechanics on the car. At this moment, it will stop operating, and the noise will disappear.

Carbon build-up on the engine

The phenomenon of carbon accumulation on the engine does not directly cause the Engine Knock to sound as mistakenly believed by many people. Instead, the problem will come from the plaque that reduces the engine’s ability to operate. 

Therefore, the fuel combustion process will also have many issues, including uneven combustion.

Symptoms of Engine Knock on Startup

In addition to the annoying sounds, Engine Knock can create several other problems for the vehicle when we start the engine.

Inefficient acceleration

Most of the problems that cause Engine Knock come from mechanisms that are important in increasing the vehicle’s speed. 

For this reason, you will have many problems in the acceleration aspect if you hear unpleasant sounds coming from the engine when starting. Of course, in some cases, we will still meet humming noise in car getting louder with speed again.

Abnormal vibration motor

Although not very common, the vibrations from the engine feedback through various details often appear next to the knock engine. This problem is straightforward to detect during vehicle control.

So it will take a little while to determine if this is happening.

How To Fix The Engine Knock On Startup Issue?

It is still best to take your vehicle to a shop or garage to get help. But there are still some actions that can help alleviate or even deal with the engine knock-on startup then goes away situation that we can do at home. Please follow the information below carefully for more details.

  • Check the fuel: As mentioned, problems with the power can also lead to deviations in combustion. So you need to carefully consider the fluid supply and the vehicle requirements in this respect to make the right choices.
  • Consider spark plugs: Spark plugs play an essential role in igniting the mixture of gas and fuel. Therefore, you should also check and clean this part to restore the ability to burn and eliminate the risk of causing problems in the ignition process.
  • Check the fuel filter: The fuel filter panels will help us a lot in preventing the agents that can affect the combustion process, thereby causing unpleasant noises. Therefore, problems coming from this part will cause many serious consequences. The inspection will help us to recognize and prevent this problem easily.

How Much Does It Cost To Fix This Issue?

Depending on the problem that the system encounters, you will need to pay different fees to solve engine noise on startup.

If the engine fails, we must spend $ 2,000 to $ 5000 to repair or even replace this part. This process will be even more expensive when you must pay for labor and other accessories.

In the luckier case, you will only need to spend from $ 200 to $ 600 to clean dirty parts in the engine.

In the end, you still need to spend an additional amount of money, usually less than $100, for troubleshooting replacement solutions, oils, or other substances required.


Why did my engine knock when I first started it?

Often this phenomenon occurs because the mixture of gas and fuel burns unevenly and causes a deviation in the supply of piston thrust.

Why does my engine tick on startup and then go away?

The leading cause of the ticking sound when starting the car comes from opening and closing valves or shaking hands without the help of lubricating oil.

Why does my car knock when the cold starts?

When starting the car in cold weather, the pistons will tend to contract due to the low ambient temperature. At this time, gaps will appear between the piston skirt and the cylinder wall and cause a knocking noise when starting the car.

Does Rod Knock go away when the engine warms up?

Rod Knock will not go away when you start the engine for a while and cause the machine to heat up. On the contrary, heating makes this phenomenon worse.

Can an engine knock go away?

In most cases, you can still move generally without worrying too much. However, we should still consider this carefully before deciding to move forward.


The engine knock on startup then goes away is a sign that the danger of failure is increasing. Therefore, you should refer to and carefully remember the information in the article always to be ready to handle any problems that arise while traveling with the vehicle.

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