Four Signs That Your Piston Ring Is Bad (& How to Replace It)

Pistons rings, which most people know about but have never actually seen, are something many people don't realize they even exist.

This is due to the fact that these rings are incorporated into each part of a car's engine.

However, what happens if one or more of these piston rings fails? Let’s find out!

The following article will describe the signs and locations of bad piston rings, their function, cost, and how to get them replaced. Let's start with the signs.

Bad Piston Ring Warning Signs

The most common sign of bad piston rings is blue smoke from your car’s exhaust pipe together with a sinking engine oil level.

Bad or failed piston rings are characterized by:

Because of the piston rings’ vital role, there are some major symptoms you should look out for. Below is a list that explains the symptoms associated with bad piston rings.

It is rare to see a large amount of oil. 

The piston rings can't stop oil from leaching into the cylinder if they fail; oil that leaks will be mixed with the combustion process.

Slowly and gradually, all your engine oil will leak into the cylinder, and you will witness a drop in your car’s engine oil level. This would mean that you will need to have your oil refilled more often.

It is possible to feel that your car requires oil after 3000 miles even if the oil was changed every 5000. You should immediately call your mechanic if you see this phenomenon. A professional will diagnose the engine’s valve seals and piston rings and advise to replace them if needed

Oil leakage

If the piston rings become worn, the crankcase will experience high pressure. When this happens, the seals in the crankcase begin to crack and start leaking oil. Check the crankcase pressure for oil leaks.

Let the engine sit on the idle position and open the oil cap. You should feel a slight vacuum, not pressure. If the oil cap flies away together with a lot of smoke that pours out – you may have bad piston rings.

Slow Acceleration

When the piston rings get damaged, the engine’s combustion chamber loses pressure. Because the piston is unable to compress fuel and mixture completely, the engine loses power. This causes the engine to produce less power with each cycle.

It is possible to push the throttle as hard as you like, but not have your vehicle accelerate at the same speed. You may need to replace your piston rings if you lose acceleration.

Once you replace the old ones with the new ones, you will get higher compression, and you will feel an immediate change in your vehicle’s power.

Blue Smoke Emitting From Exhaust 

Not only will weared out piston rings cause a loss in performance, but they will also cause your car’s exhaust to emit blue smoke. When the oil gets mixed up with the fuel & air mixture and burns, a thick blue cloud of smoke comes out of the exhaust. This is the most common symptom that you'll notice, as it usually appears almost instantly.

If you experience any problems, consult an expert immediately. You can't ignore a problem that is getting worse. Other engine parts can eventually be damaged which will lead to higher repairs costs.

Piston Rings Function

The piston rings help keep the combustion chamber known as the area inside each cylinder – pressurized, which makes it easy for combustion to happen. 

The piston rings are the seal between the piston and the cylinder walls to keep the combustion chamber’s pressure and oil in the crankcase. If they deteriorate or fail, your car’s engine will start losing power, and literally, hundreds of other problems may arise if they are not dealt with quickly.

Piston Rings

You will find the piston rings inside the block of your engine. They are wrapped around the pistons in a cylinder.

These are not easy to spot without the entire engine being disassembled.

Piston Rings Repair Cost

The cost of replacing a piston ring depends on its model and labor costs. The cost of the piston rings is $40 to $200, depending on how many cars you have. Labor costs between $1000 to $4000.

While piston rings may be very small in size, it is quite costly to replace them. It basically depends on your car’s make and model, but on average, you could expect to pay from $40 to $200 just for the piston rings. That doesn’t sound much but wait until you add the labor cost to the total.

Because the piston rings are deep inside an engine, mechanics must take it apart and access the innermost parts to get rid of the piston rings. The whole procedure takes time and precision.

After the piston rings are installed, it is time to reassemble the engine and place it back into its original position. Your mechanic would need to complete the job in 16 hours. Certified mechanics will likely do the job faster and in a more efficient manner.

To install the piston rings correctly – you have to measure the ring cap and fit them in the right order. Also, before you install the piston rings, make sure to measure and check for any wear on the cylinder walls. 

For a proper replacement of the piston rings, labor costs can be anywhere from $1000 to $4000 depending on your engine.

It is possible to repair them by yourself if you are skilled enough. However, you should be ready for a huge job that requires a lot knowledge.

Also, it is possible to need to repair or replace certain parts of the engine while you are taking it apart. You might even have to rebuild the engine block.

Questions about the Piston Ring