The Piston Rings Function and Bad Symptoms in Your Car


When your vehicle acts weird, you might wonder about piston rings function and bad symptoms in the car. The piston ring is a significant component of an internal combustion engine. It’s located in the piston, so to change the piston ring, the engine block has to be removed from the crankshaft. Its function is to seal the combustion chamber properly. It prevents the oil from the crankcase from getting into the combustion chamber, and air-fuel mixture to get into the crankcase. A combustion chamber is a place where the combustion process happens, while the crankcase is where the crankshaft is sitting.

Piston Rings Function and Bad Symptoms in Your Car
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Piston rings function

As mentioned before, it seals the piston and the cylinder blocks from leaking oil or air-fuel mixture. Any piston engine uses the piston ring in it. Engine like Four-stroke gasoline engine, two-stroke, and diesel engines utilize piston ring despite they work in different ways. Nowadays, most cars are four-stroke gasoline and diesel engine. These engines work similarly, so their ring piston also put in similar configuration.

Four-stroke or four-cycle engine has four different states where the piston ring is constantly working. In the induction state, the piston is moving down and sucking the air-fuel mixture into the combustion chamber. The piston ring helps to create the vacuum so that there is no air or oil from the crankcase to leak into the combustion chamber. Then, the piston goes up in the compression state. The piston ring holds the air-fuel mixture to be compressed. Then, at the combustion state, the piston is forced down by the ignition. The piston ring makes sure all of the power of the explosion is transferred into the piston. Then, in the last step, the exhaust gas is pushed by the piston into the exhaust port. The piston ring makes sure there is no exhaust gas that goes into the crankcase.

So, it’s pretty clear that piston engines play an important role in the internal combustion engine. So, when there’s abnormality, information about piston rings function and bad symptoms in the car could help you troubleshoot your car.

Bad Piston Rings Symptoms

Based information you can find on, here are signs and symptoms that you have a worn-out or broken piston ring.

Lacking Power and Decreased Performance

Piston ring seals the piston and the wall of the cylinder block from a high-pressure compression in the compression state. When the ring is broken, the air-fuel mixture could slip into the crankcase. This phenomenon causes the compression to drop. As the engine loses its compression, the power drops. The performance of the engine is decreasing. As you put your foot into the gas pedal, it might not respond as quickly as it normally should. The engine feels to struggle more. Usually, mechanic recommends to check is the piston ring and head gasket.

Excessive Grey Smoke

When the piston ring is broken or worn out, it might start to slip oil from the crankcase into the combustion chamber. When it happens, the engine oil will be burnt along with the air-fuel mixture. It signifies that the piston ring needs replacing. But grey smokes could also mean other fuel leaks that went into the engine, like from valve seal, turbocharger, and head gasket.

Diminished Engine Oil

The broken piston ring loses its ability to seal the piston and the wall cylinder. Therefore, the engine oil from the crankcase might leak into the combustion chamber. Sometimes, it creates grey smokes, sometimes there are no smokes. The oil loss from the crankcase reduces the total oil on the oil pan. So, when you check the dipstick and find out that the oil is decreasing, you might suspect the piston ring and valve seal. If the valve seal is good, then there is strong indication that the piston ring needs change.

If the oil let to dry, the engine condition could be worse. Eventually, the piston could be jammed in the cylinder wall. It means bad news because you have to overhaul the engine. So, it’s better to know about piston rings function and bad symptoms in the car and do preventive maintenance before the worst things happen.