---
# System prepended metadata

title: Top Reasons Why A Car Produces Knocking Sound

---

# Top Reasons Why A Car Produces Knocking Sound

![](https://i.imgur.com/CuBXbH3.jpg)

When it comes to identifying a risk for your car, the check engine light is second to none. But, there are other accurate ways to identify particular, yet critical, issues in a car.

Certain types of sounds offer more accurate identification of certain problems with a car. The knocking sound is one of them. There is a huge list of issues that can cause an engine to produce a knocking sound. Let’s have a look at these issues when your car has started making such sounds.

### Carbon deposits inside the combustion chamber
![](https://i.imgur.com/VQSeWOT.jpg)


The most common and simplest of problem is carbon deposit inside the combustion chamber or on other necessary components.

However, the carbon build-up usually happens, but it occurs rapidly if there are regular instances of misfire or a half hearted combustion process. The carbon usually starts to build up near pistons, across the cylinder heads. It does take place on other parts of your engine too.

An older car is more prone to such a problem and requires more frequent inspections, particularly of the cylinder. However, never ignore a knocking sound under the hood in any case and consult a mechanic at Service My Car.

### Is this low engine oil level or pressure?
![](https://i.imgur.com/xlVSysS.jpg)


When there is the greatest amount of mechanical movement occurring, what happens without proper lubrication? Without a doubt! Metals will collide and crush one another, and low oil levels can lead to a number of issues. While opening a valve, there could be troublesome lifters. Timing chain issues are a possibility.

The air-to-fuel ratio would be off, and the engine would undoubtedly misfire, preventing a fair combustion process.

Furthermore, using the wrong oil can result in issues. To ensure proper flow, the viscosity of the oil must be correct. Lubrication problems arise in extremely cold temperatures when the wrong viscosity oil is in use.

Besides, a major cause of knocking is low oil pressure. As oil lubricates a huge number of parts such as a camshaft, lifters, valves, or cylinder head, the distance between parts get exposed, and there might be an occurrence of knocking.

However, you should speak with a consultant for advice. Simply head over to Service My Car.

### Is there a need of fresh spark plugs?
![](https://i.imgur.com/1hD0aHO.jpg)


Since an adequate spark is always required for ignition, a damaged or worn spark plug may start to default, which causes the engine to misfire.

Since the plugs aren't sparking properly and aren't burning the fuel during each revolution, these misfires can result in unburned fuel in some cylinders. This might resemble an engine knock.

Just get it checked by an expert at Service My Car and opt for spark plug replacement if needed.

Is it bad fuel supply due to improper air in the fuel mixture?

The combustion process is complete when sparks finish the ignition of the air-fuel mixture and generate the required power.

However, there might be an instance of excess oxygen in the air to fuel mixture. In such a case, there will be less fuel to burn as compared to oxygen, which usually results in multiple detonations and a knocking sound. Over a period of time, it may have detrimental effects on the internal parts of an engine.

The common causes link to engine components that regulate or control the flow of both air and fuel. Make sure the oxygen and mass airflow sensors are functioning properly, and check that the fuel injectors and pump are in working order.

### Is it a damaged crankshaft or bearings?
![](https://i.imgur.com/mcTaFYZ.jpg)


Crankshaft facilitates motions of pistons, however, if it breaks, there would be a problem for engine process. This is quite visible inform of engine making knocking sound.

Sometimes, the connecting rod bearings may get damaged if it is not the camshaft itself. However, it happens while a vehicle is idling mostly.

### Is it engine timing belt or chain issues?
![](https://i.imgur.com/0YYPyz1.jpg)


As the timing chain connects the crankshaft and camshaft to allow synchronization of pistons, it also facilitates the valves open and close movement.

However, a mere default may hamper the combustion, leading to multiple explosions that result in engine knocking.

Usually, the timing chain gets loose or breaks, while sometimes they face issues with the tensioner. Though this requires a quick inspection or possibly a timing belt replacement at Service My Car.

### Is it wrong fuel making things bad for your engine?
![](https://i.imgur.com/7q0R1Gu.jpg)


You should be aware that there are numerous fuels on the market. Different fuels have a range of octant levels, typically, they are measured in octane numbers like 87, 90, etc. However, some of them are not suitable for a certain class of vehicle, and if you fill your tank with the incorrect fuel, pressure will build up in some cylinders that aren't receiving enough oxygen, giving your engine a knocking sound.

Whatever the cause, an engine needs immediate attention. There's a good chance that your tardiness will haunt you.

The list of knocking causes above, if ignored, can result in even worse outcomes, including catastrophic engine failure, for which an entire engine replacement or rebuild is the only workable fix. If you need any type of car service & repair, service my car provides you free pickup and delivery at the nearest [audi service](https://servicemycar.com/uk/audi-service-bolton) center.

Service My Car is here to make your life easy while offering your car maintenance at a very affordable price. You have to just book a car service or order a car repair through our website or app.