Things that Cause Knocking Noise from Vehicle When Accelerating - Service Information to Know from Hanson KIA

There are many circumstances in which knocking is pleasant. Friends showing up at your door, a child telling a knock-knock joke. Opportunity might even knock! But one place you don't want to hear knocking is from your car. If you do, it could be due to one of the problems listed below. Since all of these could be serious, it's best to schedule an appointment to have your Kia inspected if you hear a knocking, pinging, or tapping sound.

Dual-cam valvetrain

3. Valvetrain Problems

In order for combustion to occur in the cylinders, intake valves must allow the fuel and air mixture in, while exhaust valves need to let out the exhaust gases. These valves are part of the valvetrain. The knocking sound caused by valvetrain problems is sometimes described as a ticking, tapping, or rattling. Often, it's caused by hydraulic valve lifters that need attention, though it may also be due to too much clearance between the various valvetrain components.

Piston connecting rod and other engine components

2. Rod/Crankshaft Knock

The crankshaft is connected to the pistons by way of connecting rods. Having the right amount of clearance between the crankshaft and the connecting rods, accomplished by connecting rod bearings, is vital. This clearance allows the oil to pass through and prevent metal from grinding against metal. Low oil pressure, low-quality oil, and going too long between oil changes can all increase the clearance. Too much clearance causes a knocking noise as metal clatters against metal. At this point, it's probably too late for your engine.

Spark plug

1. Pre-Ignition/Detonation

The engines that power gas vehicles rely on precise timing. A mixture of air and fuel is introduced into the combustion chamber and compressed by a piston; once it's compressed, the spark plug creates a spark, and the air/fuel mixture combusts. That's how it should happen, anyway. Pre-ignition happens when the air/fuel mixture combusts before the spark is introduced, and it can cause a knocking noise that's also sometimes described as a pinging. One common cause of pre-ignition is using the wrong kind of fuel. It takes less compression to make lower-octane fuel combust. While most Kia models are built to use regular gas, premium gas is recommended on some vehicles, like the 2020 Kia K900 and the 2020 Kia Stinger.

However, there are other things that could cause pre-ignition. The knock sensor is designed to detect engine knock and make adjustments as necessary to avoid it; a broken knock sensor might give the wrong input or no input at all, making pre-ignition more likely. A carbon buildup could also cause this problem, as could an overheating engine. Whatever the cause, this is something that should be looked at immediately.

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  1. Hanson Kia

    2300 Carriage Loop SW
    Olympia, WA 98502

    • Sales: (877) 816-5820

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Hanson Kia

2300 Carriage Loop SW
Directions Olympia, WA 98502

  • Sales: (360) 339-5079
  • Service: (360) 339-5079
  • Parts: (360) 339-5079


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