5 Bad Piston Rings Symptoms Revealed!

Find out if you’re overpaying on car insurance using our cost calculator! Save money by comparing quotes from over 30 of Canada’s top insurance providers!

The best part? It’s FREE!

Bad Piston Rings Symptoms

Bad piston rings can cause several problems for your engine, including decreased performance, increased oil consumption, and poor fuel economy.

The causes of bad piston rings can include regular wear and tear, a lack of proper maintenance, or even damage caused by an accident. Luckily, there are a few things you can do to help prevent them from wearing out prematurely.

In this article, we’ll look at what those things are, as well as how to replace worn piston rings if necessary.

What are Piston Rings?

Piston rings are a set of small metal rings that sit on the outer edge of the piston in an internal combustion engine.

They have several important functions, including sealing the combustion chamber so that gases don’t escape and providing a surface for the piston to ride on as it moves up and down in the cylinder.

What are the Major Types and Functions of Piston Rings?

Piston rings come in a variety of shapes and sizes, but they can generally be divided into three major categories with respect to their function:

Compression Rings; Sealing the Combustion Chamber

Compression rings are the most important type of piston ring regarding engine performance. They’re responsible for sealing the combustion chamber so that the combustion gases don’t escape.

During the engine cycle, the piston moves up and down in the cylinder. As it does so, the compression ring expands and contracts to maintain a seal.

This is a critical function, as it ensures that the maximum power is generated from each combustion event. Because if any gases are leaking out of the combustion chamber, it means that less power is being generated.

Compression rings also play a major role in the scavenging process, which is how an engine gets rid of exhaust gases.

Secondary Rings; Aiding in Heat Transfer & Preventing Dust

Secondary rings are located below the compression rings and have a few different functions. One of their primary functions is to prevent debris and dust from entering the combustion chamber. They do this by creating a seal between the piston and cylinder wall.

Another important function of secondary rings is to aid in heat transfer. It is critical to remove heat from the piston as it moves up and down in the cylinder.

If too much heat builds up, it can cause the piston to expand and seize up, damaging the engine. The secondary rings help to remove some of this heat by conducting it away from the piston and into the cylinder walls.

The coolant running in the water jackets between the cylinder wall and the engine block takes care of the rest.

Oil Control Rings; Providing Lubrication

Oil Control Rings

The second type of piston ring is the oiling ring. As its name suggests, the primary function of the oil ring is to lubricate the cylinder walls. It does this by directing oil from the crankcase into small channels cut into the piston.

The oil then flows down these channels and onto the cylinder walls as the piston moves up and down. This helps to keep friction levels low, which in turn improves engine efficiency and longevity.

Sometimes when your oil control rings go bad, the car losses oil without any smoke or exhaust. This is due to internal leakage. Watch out for this.

Symptoms of Bad Piston Rings

If you suspect that your engine has bad piston rings, there are a few symptoms to look out for:

  1. Excessive Engine Smoke
  2. Engine Oil Leaks
  3. Excessive Oil Consumption
  4. Poor Engine Performance
  5. Dirty Air Filters

Let us take a quick look at each of these symptoms in more detail.

1. Excessive Engine Smoke:

One of the most common symptoms of bad piston rings is excessive engine smoke. If the rings are worn out, it will allow oil to enter the combustion chamber and burn along with the fuel.

Damaged piston rings will allow a large amount of smoke to be emitted from the exhaust pipe. The color of the smoke can vary, but it will typically be blue or white.

In some cases, it may even be black if there is a lot of oil burning in the engine. Another thing to remember is that not all engine smoking is caused by bad piston rings.

For example, if you see black smoke coming from your exhaust pipe, it could also indicate a rich fuel mixture. This is where the fuel and air mixture contains too much gasoline and not enough air. or you might have a bad catalytic converter.

It’s also possible to have white smoke from the exhaust pipe if the engine is cold. This is perfectly normal and should go away once the engine warms up.

If you’re unsure about what’s causing the smoke, it’s best to consult a mechanic or take your car to a dealership for a diagnosis.

2. Engine Oil Leaks:

Another common symptom of bad piston rings is engine oil leaks. The oil control ring at the piston’s bottom can become worn. This ring is responsible for scraping excess oil off the cylinder walls and returning it to the crankcase.

If it becomes damaged or worn out, it will not be able to do its job properly, and oil will build up on the cylinder walls. Eventually, this oil will find its way past the piston rings.

Worn-out pistons can also cause oil leaks at the base of the piston, where it meets the connecting rod. This can allow oil to drip down onto the crankshaft and eventually end up on the ground underneath the car.

If you notice that your engine oil level is dropping or there are oil puddles under your car, it is important to have the problem checked out by a mechanic. Worn-out pistons can cause serious damage to your engine and should be repaired as soon as possible.

3. Excessive Oil Consumption:

A very common symptom of bad piston rings is excessive oil consumption. There can be only two root causes for excessive oil consumption in any engine:

  • The engine is leaking oil
  • The engine is burning oil

Now, if the engine is leaking oil, that would be easy to spot because you would see oil puddles under the car.

But if the engine is burning oil, it can be a little more difficult to detect. The best way to tell if your engine is burning oil is to check the oil level on the dipstick.

If you notice that you have to add oil more frequently than normal, it’s a good indication that your engine is burning it. Another way to tell if your engine is burning oil is by looking for blue or white smoke from the exhaust pipe. As we mentioned earlier, this smoke will typically have an oily odor.

If you suspect your engine is burning oil, it’s important to have it checked out by a mechanic as soon as possible. Burning oil can cause serious damage to your engine and should be repaired before it gets worse.

4. Poor Engine Performance:

One of the most common symptoms of bad piston rings is poor engine performance. This can manifest itself in a few different ways.

For example, you may notice that your car is idling rough or that it’s having trouble starting. In some cases, you may even see an increase in fuel consumption. If you notice any of these problems, it’s important to have your car checked out by a mechanic.

You might also notice that your car doesn’t have as much power as it used to or that it’s taking longer to accelerate. Low compression in one cylinder or failed compression test can also indicate bad piston rings.

5. Dirty Air Filters:

Another symptom of bad piston rings is dirty air filters. The oil control ring is responsible for scraping excess oil off the cylinder walls and returning it to the crankcase.

If it becomes damaged or worn out, it will not be able to do its job properly, and oil will build up on the cylinder walls. This oil can eventually make its way past the piston rings and into the engine’s air intake system.

Once there, it will coat the air filter and prevent it from doing its job properly. As a result, your engine will have to work harder to breathe, which can lead to poor performance.

What Causes Bad Piston Rings?

The most common cause of bad piston rings is wear and tear. As an engine runs, the piston rings rub against the cylinder walls, and this friction eventually wears them down. This can happen gradually over time or all at once if the engine suffers a sudden mechanical failure.

Bad piston rings can also be caused by deposits of carbon buildup on the rings or in the cylinders. Carbon deposits can come from various sources, including oil, fuel, and coolant leaks. When these deposits build up, they can cause the piston rings to stick in the cylinders, leading to a loss of compression and power.

Another thing that can cause the piston ring wear is a lack of lubrication. If the engine is not properly lubricated, the piston rings can wear down prematurely. Oil pressure can get too low if the oil level is low or if the oil is not changed frequently enough.

Sometimes bad piston rings can also be caused by an installation defect. In some cases, the piston rings may not be properly seated in the cylinders, or they may be made from inferior materials that are more susceptible to wear and tear.

Engine overheating is also a killer of piston rings. When an engine overheats, the metal rings expand and then contract quickly as the engine cools down. This repeated expansion and contraction can cause the rings to crack or break.

These are pretty much the most common causes of bad piston rings!

How to Fix Bad Piston Rings?

If your piston rings are worn out, there are a few things you can do to fix the problem temporarily.

1. Try a Sealant Tube:

If you have a sealant tube, you can try to put it into the cylinder and see if that fixes the problem. A sealant tube can help to fix worn piston rings. It works by filling the gaps between the rings and the cylinder walls with durable, pliable material.

This material will help to create a seal that will prevent oil from leaking past the rings and into the combustion chamber.

2. Try Cleaning the Engine Head:

Another temporary fix for worn piston rings is to clean the engine head. This will remove any oil or debris that may be causing the rings to leak.

3. Try Replacing the Oil:

You can also try replacing the oil in your engine. This may help to lubricate the rings and prevent them from leaking. It is important to use high-quality oil, as this will help extend your engine’s life and prevent future problems.

How to Prevent Piston Rings Wear?

Piston rings and cylinder walls are subject to a great deal of wear and tear. To prevent this wear, it is important to take some preventative measures.

  • One way to help prevent piston rings from wearing out prematurely is to ensure they are properly lubricated.
  • Try adding oil additives to the engine oil. These additives will help coat the piston rings and cylinder walls, reducing friction and wear.
  • Another way to prevent piston rings from wearing out prematurely is to use higher-quality piston rings.
  • Many aftermarket options are available that are made from better materials and will last longer than the stock piston rings.
  • Another advice one can give is to avoid running the engine at high RPMs for extended periods. This can cause the piston rings to wear out prematurely.
  • If you must run the engine at high RPMs, be sure to use a lower gear ratio so that the engine is not under as much stress.
  • A golden tip is to have your engine regularly serviced by a qualified mechanic. This will help to ensure that all the moving parts are properly lubricated and that there is no excessive wear on any of the parts.

By following these simple tips, you can help to prolong the life of your piston rings and cylinder walls.

Piston Rings Replacement Cost

Replacing piston rings is one of the most expensive and labor-intensive tasks a mechanic can undertake. The cost of the replacement job will vary depending on the make and model of your vehicle, as well as the size of the engine.

In most cases, you can expect to pay between $900 and $1,800 for a complete piston rings replacement job. The piston ring set will typically cost between $100 and $300. It is the labor that is going to be the most expensive part of the job.

A qualified mechanic usually charges between $100 and $200 per hour for their labor. This typical replacement job will take between 4 and 8 hours to complete. So, labor charges will make up the majority of the total cost.

The job also uses many specialty tools, such as piston ring pliers, which is why it is difficult to perform at your home.

One more thing you need to add to this list is the cost of an oil and filter change. This is something that most mechanics will include in the total cost of the job.

The bottom line is that replacing piston rings is not a cheap job. But, it is something that needs to be done from time to time to keep your engine running properly.

If you think you have faulty piston rings, it is best to take your vehicle to a qualified mechanic for an inspection. They will be able to tell you for sure if they need to be replaced and give you an estimate of the total cost of the job.


Bad piston rings can cause a lot of problems for your engine. But, if piston rings fail, it is imminent to take care of it as soon as possible. It may lead to a seized engine.

Be sure to keep an eye out for the symptoms of bad piston rings and have your vehicle inspected by a qualified mechanic at regular intervals. By doing this, you can help to prevent serious damage to your engine and avoid costly repairs down the road.

Do you have any tips on how to prevent bad piston rings? Let us know in the comments below! If you enjoyed this article, please share it with your friends! Thanks!

Frequently Asked Question

Why is it so expensive to replace worn piston rings?

Pistons rings are buried deep within the engine, so they are not easy to replace. You practically have to disassemble the complete engine to replace them. For a skilled mechanic, the job may take 4 to 8 hours. So, it is a very time-consuming job.

Additionally, piston rings are very small and delicate. They have to be made to very tight tolerances (much tighter than most other engine parts) to seal the combustion chamber effectively. This makes them expensive to manufacture.

All of these factors combine to make replacing piston rings a very expensive repair job. If you are experiencing problems with your engine, it is important to have it checked by a qualified mechanic as soon as possible.

Waiting too long to replace worn piston rings can lead to much more extensive (and expensive) damage.

What happens when your piston rings go bad?

Piston rings are one of the most important components of an engine, and they play a vital role in its proper operation. When they go bad, it can cause several serious problems.

One of the most common symptoms of bad piston rings is increased oil consumption. If your engine uses more oil than usual, the piston rings are likely worn out or damaged. This can lead to a decrease in engine performance and fuel economy.

Another symptom of bad piston rings is increased exhaust smoke. If you notice that your vehicle’s exhaust is emitting more smoke than usual, it’s a good indication that the piston rings need to be replaced.

How long do piston rings last?

Piston rings are designed to last 80,000 to 100,000 miles. However, not all engines will last for 80,000 to 100,000 miles before needing new piston rings.

If you drive a lot of short distances or frequently operate your vehicle in stop-and-go traffic, it can cause the rings to wear out more quickly.

Additionally, if you don’t regularly change your oil or use lower quality oil, it can also shorten the lifespan of your piston rings.

What do bad piston rings sound like?

Bad piston rings will usually produce a loud knocking noise from the engine. The knocking noise is caused by the piston rings not sealing properly against the cylinder walls.

This allows oil and gas to leak past them. This can cause a loss of power and efficiency and eventually lead to irreparable engine damage.

Is it necessary to change engine oil while replacing piston rings?

Yes, it is necessary to change engine oil while replacing piston rings. The new piston rings will not seat properly without clean, fresh oil. Also, the old oil will likely be contaminated with metal shavings and other debris from the worn-out piston rings.

These contaminants can damage the new piston rings and cause premature wear. Therefore, it is essential to change the engine oil when replacing piston rings.

Can bad piston rings ruin your engine?

Bad piston rings can ruin your engine by causing it to overheat. The rings can also cause oil to leak into the combustion chamber, which can lead to fouling of the spark plugs and damage to the engine’s valves.

In severe cases, the piston rings can cause engine seizure, damaging the engine beyond repair. Therefore, it is important to keep an eye on your engine’s oil level and condition and to have the rings replaced if they show signs of wear.

Sign up for our Newsletter

Related Articles