Your car is a combination of thousands of different parts made from various materials.
The engine compartment consists of many metal parts, while the engine itself is made of cast iron. The various gears inside the car are made of pure metal, while the tires on which the car stands and rolls are made of rubber. The interior is mostly plastic, and that’s pretty much what a car is made of.
But while you’re driving, your car tends to vibrate. With new cars, the vibration sounds aren’t so easy to hear because the car is new and everything is firmly installed. Even the engine will run smoothly and seamlessly without making any noise or sounds that might be uncomfortable for the driver’s ears.
Common Car Engine Noises
As a car ages, parts tend to loosen. The parts inside start to come loose due to vibrations caused by driving on uneven roads and different surfaces. There are noises that a driver gets used to as their car gets older, but there are also noises that seem to come from the engine that are not common. However, the question is, what could be causing this noise or sound, and is it okay to ignore it since the car is running fine?
Here are the 5 most common engine noises from engines and their possible causes:
1. Engine Knocking Noises
This noise is usually heard when you’re driving your car, changing gears, and accelerating. The sound seems as if something inside the engine is knocking hard against the engine. This is usually the result of premature ignition of the air-fuel mixture, which is supposed to burn at the right time to produce optimal performance. The ignition is timed, so there could be a problem with the mixture’s timing. In such a case, a proper engine tune-up might solve the issue.
If the problem persists, the cause could be something more serious, like a worn-out part inside the engine. In this case, the repair could be costly, as the engine would be disassembled to fix the problem. Some cars have a knock sensor that controls exactly this. Sometimes these sensors can be faulty. Replacing the sensor solves the problem.
If you experience engine knocking, make sure your engine oil level is correct, and if you can locate the problem, consult a mechanic.
2. Rattling During Cold Start
Some modern engines naturally vibrate very strongly during a cold start. This is often due to a timing chain attached to the engine. As the engine ages, it starts to shake more and more during cold starts, indicating that the timing chain is worn out. If you know you have a timing chain in your car and it rattles badly during a cold start, you should definitely have it checked further, as a bad timing chain can seriously damage the engine if it fails!
It’s not easy to check a timing chain yourself without almost completely disassembling the engine. If you suspect a bad timing chain, ask a mechanic with a diagnostic tool to perform a proper diagnosis before replacing it!
3. A Constant Clicking or Tapping While the Engine is Running
This noise is one of the most common engine noises and usually points in the direction of the engine’s lifters, also known as the upper valve train. This valve train or lifter controls the movement of the air intake and exhaust valves. These are accessible by removing the engine head. The lifters rest against springs that return the lifters to their original position after movement by the cam inside.
This noise normally occurs when the engine oil pressure is low or when the springs or camshafts are worn out. Make sure the car has enough oil by checking the oil level with the dipstick.
4. Squeal or Loud Howl When You Accelerate
Again, this is one of the most common engine noises. In fact, the noise doesn’t really come from inside the engine but rather from the belts. Your car has several belts, one for the power steering pulley, one for the AC compressor, and one for the steering (if the belt is rubber and not a chain). This noise is usually louder when you start the engine cold and fades when you accelerate to high speeds. This noise is caused by one of the two belts slipping on the pulley. This could be due to the belts loosening or simply wearing out. It’s best to replace worn belts before they completely tear.
Try tightening the serpentine belt to see if it makes a difference. You can also spray any type of liquid if the squealing is constant, to see if the noise goes away.
5. Grinding Noise When You Shift Gears
This is a problem for vehicles with manual transmissions. A grinding noise when shifting gears is a common engine noise, especially in older cars. The noise is related to the gearbox but doesn’t necessarily mean the gearbox is faulty. This noise means that the gears inside the gearbox are grinding hard against each other because either the clutch isn’t fully separating the gearbox from the engine, or the driver isn’t pushing the clutch properly before shifting gears. This noise is often heard when new drivers are learning to drive with the gear lever. If the problem isn’t related to driving style, the clutch mechanism may be worn out. In this case, the clutch system needs to be replaced.
Conclusion
Many engine noises come from a low engine oil level or other fluids. Always check the engine oil level with the dipstick first if you hear a noise. The next most common thing is a bad serpentine belt that can cause squealing. Remove the serpentine belt to see if the noises disappear.