Car Engine Knocking Sound: Causes and Solutions

A knocking sound coming from your car engine is never a good sign. It can be a symptom of a serious problem that needs to be addressed as soon as possible.

There are a few different potential causes of a knocking sound in your car engine. The most common cause is a lack of lubrication. When your engine is not properly lubricated, the metal parts can rub against each other and create a knocking sound.

Other potential causes of a knocking sound in your car engine include:

Worn or damaged spark plugs
Carbon buildup on the pistons
Loose connecting rods
A cracked or damaged piston
A damaged crankshaft

If you are experiencing a knocking sound in your car engine, it is important to have it diagnosed and repaired as soon as possible. Ignoring the problem can lead to further damage to your engine and costly repairs.

Causes of Car Engine Knocking Sound

Lack of Lubrication

As mentioned above, the most common cause of a knocking sound in your car engine is a lack of lubrication. When your engine is not properly lubricated, the metal parts can rub against each other and create a knocking sound.

There are a few different ways that your engine can become under-lubricated. One possibility is that your oil level is low. If your oil level is low, it is important to add oil as soon as possible. Another possibility is that your oil filter is clogged. If your oil filter is clogged, it will not be able to filter out contaminants from the oil, which can lead to engine damage.

Worn or Damaged Spark Plugs

Worn or damaged spark plugs can also cause a knocking sound in your car engine. When spark plugs are worn or damaged, they cannot properly ignite the fuel in your engine. This can lead to incomplete combustion, which can cause a knocking sound.

Carbon Buildup on the Pistons

Carbon buildup on the pistons can also cause a knocking sound in your car engine. Carbon buildup occurs when fuel and oil burn incompletely in your engine. This carbon buildup can accumulate on the pistons and cause them to stick. When the pistons stick, they can create a knocking sound.

Loose Connecting Rods

Loose connecting rods can also cause a knocking sound in your car engine. Connecting rods are the parts that connect the pistons to the crankshaft. If the connecting rods are loose, they can cause the pistons to slap against the cylinder walls, which can create a knocking sound.

A Cracked or Damaged Piston

A cracked or damaged piston can also cause a knocking sound in your car engine. When a piston is cracked or damaged, it can allow compression to leak out of the cylinder. This can cause the piston to knock against the cylinder walls.

A Damaged Crankshaft

A damaged crankshaft can also cause a knocking sound in your car engine. The crankshaft is the part of the engine that converts the reciprocating motion of the pistons into rotating motion. If the crankshaft is damaged, it can cause the pistons to knock against the cylinder walls.

Solutions for Car Engine Knocking Sound

The solution to a knocking sound in your car engine will depend on the cause of the problem.

Lack of Lubrication

If the knocking sound is caused by a lack of lubrication, the solution is to add oil to your engine. It is important to use the correct type of oil for your engine. You can find the correct oil type in your vehicle’s owner’s manual.

If adding oil does not solve the problem, you may need to have your oil filter replaced. A clogged oil filter can prevent oil from reaching the engine’s moving parts.

Worn or Damaged Spark Plugs

If the knocking sound is caused by worn or damaged spark plugs, the solution is to replace the spark plugs. It is important to replace all of the spark plugs at the same time, even if only one spark plug is causing the problem.

Carbon Buildup on the Pistons

If the knocking sound is caused by carbon buildup on the pistons, the solution is to have the engine decarbonized. Decarbonization is a process that removes carbon buildup from the engine. There are a few different ways to decarbonize an engine, including using a commercial decarbonization product or having the engine professionally decarbonized.

Loose Connecting Rods

If the knocking sound is caused by loose connecting rods, the solution is to have the connecting rods tightened. This is a job that should be performed by a qualified mechanic.

A Cracked or Damaged Piston

If the knocking sound is caused by a cracked or damaged piston, the solution is to replace the piston. This is a job that should be performed by a qualified mechanic.

A Damaged Crankshaft

If the knocking sound is caused by a damaged crankshaft, the solution is to replace the crankshaft. This is a job that should be performed by a qualified mechanic.