4 Common Bad Piston Rings Symptoms – Causes and Fixes

Fundamentally, the internal combustion engine hasn’t changed all that much in the past 150 years. The suck, squeeze, bang, and blow are still present. Otherwise, that is a generalized explanation of how fuel and air are burned.

Newer technologies usually seem to make engines slightly more effective at what they do, though. You should be concerned about the cost of correcting bad piston rings symptoms because of this.

The majority of modern engines depend on these piston rings. They ensure that the engine in your automobile won’t wear out over time and keep it operating smoothly and powerfully.

Therefore, it should come as no surprise that many individuals express anxiety when they notice damaged or worn-out piston rings. What are some typical car bad piston rings symptoms in light of this?

Piston Rings: What are They?

Before we get into the infamous bad piston rings symptoms, it’s important to take some time to learn more about what they do. What exactly are piston rings then?

I suppose we’re all familiar with what pistons are. They fit perfectly inside the cylinders of your engine. The compression and ignition of the fuel and air inside the combustion chamber force the pistons up and down.

An explosion can be converted into a force that your car can use to move forward and backward by moving the piston up and down.

This motion starts with the pistons, travels through the crankshaft and transmission, and eventually turns the wheels of your car. In light of this, you also need to realize that the pistons have a substantial amount of fluids to manage.

High-pressure gasoline and air, which is technically a fluid, are placed on top of the pistons. However, the mechanism is kept lubricated by the copious gallons of motor oil underneath the pistons.


Piston rings are frequently made to last for a very long time, if not forever. Because of this, the majority of you will eventually have to deal with the signs of faulty piston rings.

It’s a massive no-no to mix oil and petrol, as we’ll discover in greater detail later. Additionally, we need to be concerned with exhaust gases, which are produced after the fuel and air have ignited.

How then does the piston maintain their separation? Our pals, the piston rings, then enter the picture. No matter if your engine is an inline-4 or a V12, each piston in each cylinder has piston rings.

These spring-loaded metal rings fill the spaces between the stationary cylinder walls and the moving pistons. These rings essentially keep these fluids apart.

Which are the Most Common Automotive Piston Ring Types?

Modern automobiles frequently have three piston rings per cylinder. While one ring retains and directs engine oil to the proper location in the car, the other two keep combustion gasses at bay. The various varieties of piston rings and their functions in the engine are listed below.

1. The Pressure Compression Piston Rings

As they seal the top of the piston, pressure compression rings have the responsibility of preventing gas leakage. These rings can be found in a variety of places depending on the vehicle, although they are commonly located in the main piston grooves.

These rings aid in the transfer of heat from the piston to the walls of the piston. The oil layer that the oil ring has left behind is sheared by the compression rings.

In an automobile engine, compression rings typically have a rectangular or keystone cross-section. The top compression ring for the periphery usually has a barrel shape, whilst the lower compression ring often has a tapered Napier face.

While in the past, simple plain-faced rings were used, some engines additionally use a taper facing for the top ring.

2. The Wiper Piston Rings

Under the compression ring is the wiper ring, commonly referred to as a Napier ring or backup compression ring. Their main function is to remove extra oil from the liner surface and serve as a backup support ring for any gas leaks that occur below the top compression ring.

To produce a wiping action as the piston moves closer to the crankshaft, the majority of wiper rings include a taper angle face at the bottom.

When wiper rings are improperly positioned and develop bad piston rings, more oil is removed from the combustion chamber, increasing oil consumption.

3. The Scrapper Oil Control Piston Rings

As implied by the name, scrapper oil control rings are in charge of controlling the flow of lubricant through the cylinder walls. The oil was evenly distributed by the rings throughout the liner’s diameter.

The oil that has been spilled on the cylinder walls is removed by scrapper rings. The crankcase receives the scraped oil back. The small space between the ring and the cylinder is also prevented from flowing with oil thanks to them.

Oil control rings are often made from a single piece of cast iron, several pieces of steel, or steel/iron with a helical spring backing to give the tension required for a close seal. The two scraping zones on cast iron oil rings and rings with helical spring backings differ in complexity.

Spring-loaded piston rings by Interiot~commonswiki / CC BY-SA 2.0. In some cars, these piston rings are tough enough to last for 300,000 miles. This is a rare occurrence though mainly because piston rings typically last for roughly 100,000 miles in real practice.

On the other hand, multi-piece steel oil control rings frequently consist of two thin steel rings (referred to as rails) with a spacer-expander spring between them to maintain their separation and generate radial pressure.

The piston ring gap shrinks to a few thousandths of an inch when it is inside the cylinder bore. Six different ring gap forms can be used: step cut, hook step, miter step, square cut, and angle cut.

In essence, piston rings function in sets of three, starting with the top compression ring and moving on to the second groove ring and the oil control ring. They serve to contain combustion gases, aid in heat transfer to the cylinder wall, lubricate the wall and remove oil.

What Do the Piston Rings In the Engine Do?

It occurs to you as we walk you through the bad piston rings symptoms and what they do. What do the piston rings accomplish by keeping the various fluids in your engine at a distance?

The piston rings are in charge of four other tasks in addition to the ones we’ve already covered. So that we can better understand their significance:

  • The pistons’ seals are its primary function. This primarily serves to stop the gases, a by-product of engine combustion, from escaping the combustion chamber. This will eventually end up in the crankcase. Your car’s overall performance can suffer if these gasses leak out of the cylinders.
  • There are various advantages to preventing oil from entering the combustion chamber. It specifically aids in preventing engine oil from burning up inside, which could otherwise significantly increase the requirement to top off with oils. Additionally, it guarantees that the engine has enough lubrication.
  • Another benefit of cooling is that it facilitates contact between the pistons and the cylinder walls. A significant amount of the tremendous heat generated by the pistons can be transferred to the cylinder wall by the pistons. The heat will then be dissipated through the coolant in your car from there.
  • Last but not least, the piston rings shield the pistons from hitting the cylinder walls. The pistons must travel linearly as it oscillates up and down in strong, repetitive strokes. Otherwise, even a slight misalignment can cause it to slam into the cylinder walls, causing serious harm.

Bad Piston Rings Symptoms: What Causes Them?

In the combustion chamber, the piston rings are put under a lot of pressure. Piston rings may become damaged if the gas produced inside the combustion chamber has a higher combustion pressure than usual.

This can happen when the fuel is mixed with dirty air or when a malfunctioning injector causes the gasoline to detonate and ping.

The performance of the ring will also be harmed by contaminated fuel oil or poor-quality cylinder oil. The ring’s ability to seal the combustion gases will become clear as it ages.

Poor fuel or cylinder oil quality, an inefficient combustion process, improper fuel timing, a worn liner, and other factors are among the most frequent causes of piston ring deterioration.


Pistons within a sectioned petrol engine by 160SX / CC BY-SA 3.0. Because of the potentially high engine heat, the pistons’ metal may expand. As the larger pistons start to scrape against the cylinder walls, more damage will be done. There will be a devastating engine failure very soon.

The most common sign or indicator of a worn ring is blowby, which is gas that enters the crankcase or the area beneath the piston. Wear can lead to sticky rings brought on by carbon or sludge deposits, as well as ring splitting or cracking.

Which are the Most Common Bad Piston Rings Symptoms?

Piston rings are typically built to endure a long period, if not forever. As a result, the majority of you will eventually have to deal with bad piston rings symptoms.

These piston rings are strong enough to survive 300,000 miles in some vehicles. The majority of piston rings have a practical lifespan of about 100,000 miles, thus this is an unusual occurrence.

All things considered, you should be on the lookout for bad piston rings symptoms caused by wear and tear, which can be normal.

However, without proper maintenance or care, the piston rings’ health (and useable shelf life) could degrade significantly more quickly. How can you tell if you need to consider an urgent diagnosis of bad piston rings symptoms in light of this?

Here are just a few bad piston rings symptoms that you should be aware of:

1. An Abnormal Growth In Oil Consumption

Higher oil consumption is the most visible result of worn-out or damaged piston rings. Have you recently found yourself needing to top off the motor oil more frequently? Perhaps after traveling only a few hundred miles, you had to see the neighborhood mechanic for an entire quart? This is not typical.

In this scenario, defective piston rings would be the primary suspect. They risk allowing engine oil to flow through the rings and into the cylinders when their seals deteriorate. It will ignite once it enters the combustion chamber together with the fuel and air mixture.

As time goes on, more and more of the oil will burn off. As the dipstick reads lower each time you check the oil, you’ll soon notice this. If your car has a low oil warning light, it can also start to come on.

Additionally, it’s not only oil burning. The pressure on the oil flow in the crankcase increases significantly when the piston rings fail. The seals and gaskets that hold your oil in place may begin to wear out earlier if left to their own devices. Finally, there are oil leaks, possibly quite a few of them.

2. Excess Colored Smoke Emanates from the Exhaust Pipe

Burning oil inside the combustion chamber has the effect of throwing the mixture off balance. The motor oil will make sure that the gasses flowing out of the exhaust are visible when this is ignited with the fuel and air.

You’ll see large plumes of smoke since the catalytic converters are unable to remove the byproduct of burning oil. The exhaust fumes can seem dark gray, white, or blue rather than clear.

3. Performance Loss and Weak Acceleration

When it comes to effective and powerful combustion, engine compression is crucial. Without sufficient compression, the air and fuel mixture cannot provide enough force to move your car if it is ignited. Less horsepower is produced on each cycle due to pressure loss.


Excess-colored smoke from the exhaust by Ruben de Rijcke / CC BY-SA 3.0. When ignited with the fuel and air, motor oil will ensure that the gases coming out of the exhaust are visible. Due to the catalytic converters’ inability to eliminate the oil-burning waste, you will notice significant plumes of smoke. Instead of seeming transparent, the exhaust fumes can appear dark grey, white, or blue as a result of bad piston rings.

That power is permanently lost as the seals on the piston rings deteriorate because the compression leaks out and into the crankcase. This is bad because it will rapidly contaminate the engine oil with fuel or exhaust gases. Technically, this is referred to as a “blow-by.”

Poor performance, which manifests as delayed acceleration, is the most frequent result of this compression leakage. You can even experience difficulty starting your car. These typically manifest later in the life of a damaged piston ring and can cause engine failure.

Another adverse effect of blow-by is that you may notice oil in the intake of your car. Positive crankcase ventilation (PCV), which allows fumes to escape the crankcase and return to the intakes, is installed in some automobiles. The intake will become greasy if the blow-by becomes too severe.

4.  Damage to the Cylinder Walls and Engine Overheating

Now that the piston ring failure is getting worse, we’re getting into really dangerous territory. There won’t be enough motor oil in the system to adequately lube your engine when oil consumption soars. The temperature of the engine will rise as the friction increases.

The only thing left to assist cool down the engine is the coolant, and that might not be enough. Your pistons’ metal may expand as a result of the heat that may get so intense. More harm will be done as the bigger pistons begin to rub against the cylinder walls. There will soon be a catastrophic engine failure.

How Much Do Bad Piston Rings Symptoms Cost to Fix?

As we’ve learned thus far, you can’t avoid treating bad piston rings symptoms. Yes, you may be able to continue driving for a short distance to reach your nearby mechanic even when your piston rings are worn out.

But continuing to drive for too long while putting off replacing those worn piston rings might seriously harm the engine. It might fail or freeze up. The latter will need a whole new engine.

What does it cost to correct the bad piston rings symptoms then? It’s not inexpensive, as we hinted at in the beginning. Fair enough, the components themselves don’t bother me. Piston rings are often available at anywhere between $30 and $150.

However, if labor is included, the prices start to mount. Consider for a second that mechanics often earn between $50 and $120 per hour in wages.

The difficulty of replacing the piston rings means that mechanics may charge you up to $200 for this kind of labor. That time should now be multiplied by 10, which is about how long it takes to change the piston rings.

This is because the engine must be completely dismantled to access and replace the piston rings. Additionally, your pistons and cylinders might require reconditioning.

Because the piston rings are located deep inside the engine, replacing them is extremely difficult and intricate. For the total thing, you should budget between $1,500 and $2,500 to address the bad piston rings symptoms.

This includes labor and parts, as we’ve already talked about. Don’t be shocked if the cost tops $5,000 if the piston rings are difficult to access if your engine is sophisticated.


A car engine by Carolla / CC BY-SA 3.0. Three-piston rings are common in each cylinder of modern cars. The other two rings prevent combustion fumes from entering the engine while one ring holds onto and directs engine oil to the proper area inside the car.

Bad Piston Rings Symptoms Troubleshooting Guide: How Can I Do It?

If you’re fortunate, changing the piston rings might cost you a little around $1,000. Still, most people would find it difficult to cover the cost.

Fortunately, there are certain diagnostic procedures to determine whether the piston rings require total replacement.

Or, if it was repairable. Oil buildup in the cylinders is essentially the only other possible remedy for damaged piston rings.

You’ll be extremely lucky if this is the case. Specialized high-strength cleansers can be used to remove this muck from the area. Without even disassembling the engine, these can clean the piston rings.

With this modification, you can avoid paying a hefty repair bill for any bad piston rings symptoms. However, the professional will first need to do some troubleshooting procedures.

If your automobile fails these tests, you will regretfully need to completely disassemble the engine and spend a lot of money to correct the bad piston rings symptoms:

1. Performing the Compression Test

A mechanic can use this to check how effectively the piston rings are maintaining their seal in the combustion chamber. In other words, how effectively it maintains compression pressure.

2. Performing the Leak-Down Test

If the compression test was unsuccessful, the mechanic will now conduct a leak-down test. This is to check if the compression leak is entering the crankcase from below. It establishes whether the piston rings are to blame for the leak.

Is Paying to Fix Bad Piston Rings Symptoms Worth It?

Getting a bill for more than $1,000 to treat bad piston rings symptoms is undoubtedly frightening. You could question whether getting them updated at all given the enormous cost, though. We’ll have to weigh our alternatives for what to do next in light of this perplexing quandary:

1. Repairing the Piston Rings

There are more advantages than disadvantages to repairing or replacing your car if it is still relatively new and you plan to keep it in good condition for the foreseeable future. Yes, it is absurdly expensive.

However, it’s quite inexpensive compared to ignoring it, especially if the damage to the piston rings isn’t severe. Your repair bill for bad piston rings symptoms will at least be double that of an engine failure.

2. Disposing Off the Car

What happens, though, if the harm is so bad that the entire engine is in danger of dying? What if the car is simply too old or too unreliable to warrant making yet another sizable investment in it?

It can make more financial sense for you to scrap your car in this situation. Consider selling it for scrap or spare parts in this situation. Long-term, this should provide you with greater rewards.

Car engine cylinders by Kether83 / CC BY 2.5. To prevent the pistons from striking the cylinder walls, there are piston rings. While it oscillates up and down in powerful, repeating strokes, the pistons must move linearly. If not, even a small misalignment could force it to bang into the cylinder walls and do significant damage.

Fixing bad piston rings symptoms is a highly expensive task; before writing the check, you should take a step back and consider your options. Now, it’s a no-brainer if you’re fortunate enough to have a warranty to help offset the cost.

Running with damaged piston rings can cause catastrophic harm in the future. It’s not worth it if the repairs cost more than your automobile is worth.

What Entails the Bad Piston Rings Symptoms Fixing Process?

As we’ve already explained, changing the piston rings frequently necessitates disassembling the engine. It contributes to the high cost of fixing bad piston rings symptoms, which is related to labor costs.

Even yet, considering the difficulty of the task at hand, we’d say that it’s typically a cost worth paying. It’s not something you could conceivably accomplish yourself at home.

But what if you have the necessary auto expertise and experience to pull this off? Or maybe you just want to try out your ideas on a jalopy to see how it goes. In this situation, you could attempt to fix the bad piston rings symptoms yourself, however, we still don’t advise it.

To do this all right, though, will demand a significant commitment of time, effort, resources, tools, and focus.

Even if you don’t intend to MacGyver your way out of this, understanding the process a little more could help you appreciate why your mechanic is finding this so challenging.

How-to Guide for Replacing Your Piston Rings

  • Accessing the piston rings would be the first step. You might have to take the cylinder head off for this. You have to separate a lot of the related elements to do this by yourself. It involves removing all of the coolant as well as parts like the exhaust and intake manifolds.
  • The spark plug (and its wires), distributor, fuel injectors, and other components will then be disconnected. The rocker arms and pushrods are an additional component of the engine that must be dismantled.
  • You must first clean the pistons before replacing the piston rings. Scrub the area thoroughly to eliminate any dirt or impurities before you can remove the pistons. You might clean them by simply soaking them in kerosene and allowing them to air dry.
  • Take a special tool designed to remove piston rings, and now carefully remove each old piston ring one at a time.
  • Before you replace the actual rings, you should check each piston ring groove. Using a feeler gauge, check that they are within specifications as specified by your manufacturer. It could be necessary to replace the pistons as well if those grooves have worn out too much.
  • Stretch out the rings slightly and fit them over and around the piston using the piston ring tool. Make certain that each piston ring is firmly seated in the corresponding groove. After that, check the pistons again to make sure everything is in working order.
  • It’s time to reattach the pistons to the connecting rods at this point. New connecting rod bearings are a worthwhile investment when doing this.
  • Finally, reverse what you just did and put the engine’s top back together. Another excellent expenditure is to replace the head gaskets while you’re at it.


Car engine coolant by EvelynGiggles / CC BY 2.0. We are moving into really risky terrain as the piston ring failure worsens. When oil consumption soars, there won’t be enough motor oil in the system to properly lubricate the engine. As the friction increases, the engine’s temperature will rise. The coolant is the only thing left to help the engine cool down, and it might not be enough.

How Can I Avoid Bad Piston Rings Symptoms?

Dirt contamination is typically the cause of bad piston rings. The oil circuit or faulty air filters are two possible entry points for dirt into an engine. Here are some methods to assist prevent piston rings from degrading since dirt contamination is the primary cause.

1. Observe the Suggested Timing for Changing the Oil

Your piston rings’ lifespan will be lengthened if you adhere to the manufacturer’s advised oil change schedule. By doing this, you may be certain that your engine oil is clean, new, and contaminant-free.

Even while the oil filter removes debris and can help keep the engine oil clean, the oil circuits are occasionally not cleaned completely.

On the clean side of the oil circuit, there are dirt particles that have already amassed and can enter the engine’s critical components, causing wear and tear.

2. Observe the Maintenance Guidelines for the Air Filters

It’s possible for an air filter that’s long past time for a replacement to malfunction. When it develops a problem, it won’t be able to function properly, which could lead to oil leaks that could let dirt and other debris inside.

The lifespan of the piston rings can be extended and other issues can be avoided if you perform the suggested air filter maintenance and change your filter before it becomes clogged.

The Conclusion

In conclusion, repairing bad piston rings symptoms is one of the most expensive auto repairs you’ll ever have to make. The rings themselves are affordable, but replacing them is a difficult task that even experts have trouble with.

The majority of bad piston rings symptoms fixes are labor-intensive. You should budget between $1,500 and $2,500 (or perhaps more) to complete this.

But there is a less expensive option. Preventive maintenance would be this. You see, if you take proper care of your car, piston rings won’t wear out too rapidly.

A minor but important first step in taking care of your piston rings is to periodically get the motor oil changed and topped off. To keep your car’s piston rings in good condition, simply adhere to the recommended maintenance schedule.


Spring-loaded piston rings by Interiot~commonswiki / CC BY-SA 2.0