The efficient performance of the vehicle engine is very important to ensure the smooth running of the vehicle. The engine contains a piston that reciprocates inside the engine cylinder. The piston contains multiple rings that are known as the piston rings.
The main function of the piston ring is to enclose the entire piston to prevent pressure loss. When the piston ring goes bad, it produces different signs. This article explains the bad piston rings symptoms, causes, and the replacement cost.
What is a Piston Ring?
The piston ring is a metallic split ring connected to the outer circumference of a piston within a steam engine or IC engine. The piston ring is engineered to seal the space between the combustion chamber wall and the piston.
The primary function of the piston rings is to seal the engine cylinder, minimizing gas leakage into the crankcase. Moreover, they also assist in maintaining the appropriate amount of oil between the cylinder wall and the piston.
The combustion of the fuel-air mixture in the combustion chamber propels the piston, which further drives the crankshaft and generates the necessary power to run the vehicle.
An effective seal is needed along the cylinder wall to produce sufficient power to turn the piston in a single direction, preventing premature pressure release. This seal is established by using the piston ring.
Your vehicle’s piston is attached to the connecting rod, which in turn links to the crankshafts. When the piston moves down, it rotates the crankshaft, generating the momentum that drives the car.
Bad Piston Ring Symptoms
When the piston rings go bad, they produce one or more of the below-given symptoms:
- Poor Acceleration
- Poor Fuel Economy
- Poor Oil Economy
- Engine Overheating
- Higher Engine Noise
- Excessive Exhaust Smoke
- Poor Vehicle Performance
- Oil Leaks
1) Poor Acceleration
A reduction in acceleration is one of the clear symptoms of a faulty piston ring. As the piston ring of your vehicle is damaged, the combustion chamber starts to lose pressure, leading to a decrease in engine power because the piston can’t fully compress the air-fuel mixture. Consequently, the engine generates low power with each cycle.
Despite pressing the throttle to the maximum, you may not experience the expected acceleration in your vehicle. This poor acceleration could indicate the need to replace your piston rings.
Upon replacing the worn piston rings with new ones, your engine will experience increased compression and an immediate improvement in engine power.
2) Poor Fuel Economy
A reduction in fuel economy is one of the clear signs of a faulty piston ring. As the engine has to work harder to compensate for the power loss, it will require more fuel, resulting in decreased fuel efficiency.
Over time, the increase in fuel consumption will become noticeable, and it is at this point that you should consult a professional.
3) Poor Oil Economy
In case the piston rings malfunction, they are unable to prevent oil leakage into the combustion chamber, which ultimately results in oil getting mixed with the combustion process.
Over time, the engine oil will gradually leak into the combustion chamber, causing a quick reduction in the engine oil level, requiring more frequent oil refills.
For instance, if you typically change the oil every 4000 miles, you might notice the need for an oil refill by the time you reach at 2000 miles. It is crucial to take immediate action in such a situation and schedule an appointment with a professional.
Read More: Low Engine Oil Causes and Symptoms
4) Engine Overheating
If you continue to ignore the signs of bad piston rings, engine overheating can occur.
Excessive oil consumption caused by faulty piston rings leads to dangerously low oil levels, lowering engine lubrication and increasing temperatures and friction. This puts a strain on your cooling system, potentially resulting in terrible engine damage or complete engine failure.
Read More: Engine Overheating Causes
5) Higher Engine Noise
Due to the power loss associated with a malfunctioning piston ring, your engine will need to work harder to deliver the necessary power and maintain optimal performance. When the engine works harder, it results in more noise production.
While the muffler and other engine insulation parts will try to reduce some of this noise but it will still be louder than usual sound. In summary, a faulty piston ring can lead to increased noise emissions from your car.
6) Excessive Exhaust Smoke
Excessive exhaust smoke emitting from the vehicle’s tailpipe, characterized by its thick, dark gray, and blue hues, could be a clear symptom of faulty piston rings. This smoke usually comes with a burning engine oil odor.
When the piston ring of your vehicle becomes faulty, the oil may leak into the combustor. This leakage causes the oil to burn in the combustor, resulting in the thick blue-gray exhaust smoke that you observe emanating from your vehicle.
7) Poor Vehicle Performance
The most severe symptom of faulty piston rings is a complete loss of engine power.
When the piston ring goes bad, your vehicle’s acceleration and overall performance will be significantly impaired, potentially requiring a quick inspection and repair.
This extreme symptom typically occurs when you ignore the previous minor symptoms, and your engine is damaged badly.
8) Oil Leaks
Faulty piston rings can also lead to increased pressure within the crankcase, causing engine seals to go bad and leak oil. When you observe multiple oil leaks, it’s crucial to inspect the crankcase pressure. To do this, let the engine idle and gently remove the oil cap.
There should be little to no pressure and perhaps a slight vacuum. If your oil cap is forcefully ejected along with a significant amount of smoke, your piston rings may be compromised.
Causes of Bad Piston Rings
The piston rings may go bad due to the following reasons:
- Excessive Wear
- Manufacturing Fault
- Engine Overheating
- Wrong Installation
- Engine Sludge Accumulation
- Pre-ignition or Detonation
- Poor Lubrication
- Excessive Cylinder Bore Wear
1) Excessive Wear
Over time, the piston rings may wear out, particularly in high-mileage engines. High engine operating temperatures, dirty engine oil, insufficient coolant, and poor lubrication are the most common factors that lead to excessive wear.
2) Manufacturing Fault
Different quality materials are used for manufacturing piston rings. A piston ring made of poor-quality material may lead to its early failure. The piston rings may also go bad due to design flaws or improper machining during manufacturing.
3) Engine Overheating
The engine overheating for a long time may lead to thermal expansion, which may force the piston rings to stick in the piston grooves or lose their tension. The engine overheating may also lead to poor sealing and poor engine performance.
4) Wrong Installation
It is compulsory to properly install the piston rings to get optimum performance. An improper ring gap alignment or orientation may cause early wear or damage to the piston rings.
5) Engine Sludge Accumulation
Sludge accumulation in the engine may block the engine oil flow, which may lead to poor lubrication and accelerate wear on the piston ring.
6) Pre-ignition or Detonation
Unusual combustion conditions like pre-ignition may lead to build up extreme heat and pressure in the combustion chamber. This excessive heat and pressure may cause the piston ring damage or complete engine failure.
7) Poor Lubrication
The piston rings of your vehicle require a sufficient supply of engine oil to work efficiently. Contaminated or inadequate engine oil may cause the piston ring to wear out quickly and lead to failure.
8) Excessive Cylinder Bore Wear
Unnecessary cylinder bore wear may produce an improper seal between the cylinder walls and the piston rings. This improper seal may cause an increase in engine oil consumption and poor engine performance.
Piston Rings Location
Piston rings are situated within the engine block, encircling the pistons inside the engine cylinder. As a result, piston rings are not visible without disassembling the entire engine. To diagnose potential issues with piston rings, you must use a compression tester or a leak-down tester.
Piston Rings Replacement Cost
The replacement cost of the piston rings depends on some factors, such as labor cost, vehicle model, and the type of ring brand.
The average replacement cost of the piston rings is from $900 to $5200. The piston rings cost from $50 to $300.
The piston rings of your vehicle are small, but they are very costly to replace. The labor cost to replace a piston ring is very high.
How to fix bad Piston Rings?
- Before trying to repair any part, you need to ensure that the piston ring is the main source of the problem.
- Gather necessary tools and parts
- Remove the negative terminal of the battery
- Remove the coolant and engine oil.
- Disconnect all the parts (such as the exhaust manifold and intake manifold) connected to the engine block to get access to the block.
- Remove the cylinder head.
- Locate the faulty piston ring
- Gently remove the piston
- Use a ring expander to remove the faulty piston ring.
- Ensure proper cleaning of the piston ring grooves to expel the collected contaminants or carbon deposits.
- Gently install the new piston ring in its original place.
- Use using a ring compressor to reinstall the piston and all other parts in their original place.
- Turn on the engine and perform a test drive to check the performance of the piston rings.
How to Maintain Piston Ring?
- Change engine oil regularly
- Maintain the air filter regularly
- Ensure a proper supply of the engine oil
- Avoid aggressive driving
- Perform regular inspections
- Keep up with routine maintenance
- Avoid engine overheating
- Use the correct oil
How to install Piston Rings?
FAQ Section
What is the function of the piston ring?
The main function of the piston rings is to seal the engine cylinder, minimizing gas leakage into the crankcase. Moreover, these rings often assist in maintaining the appropriate amount of oil between the cylinder wall and the piston.
How long do piston rings last?
In the latest vehicles, the piston rings are designed to last for the vehicle’s entire lifespan. There isn’t a specific maintenance schedule for replacing them, and in most cases, you won’t need to change the piston rings throughout the life of the vehicle. However, if your vehicle is not properly maintained or if you’re simply unfortunate, piston ring failure can occur.
Can I replace the piston rings without removing the engine?
While it is technically possible to replace piston rings without taking off the engine, but it is generally not recommended. You will need to disconnect the oil pan and cylinder head to change the piston rings. Therefore, to easily remove these parts, it is recommended to remove the engine. Additionally, it’s important to polish the cylinder before installing a new piston ring, which is best done with a clean engine block.
Can I drive a car with bad piston rings?
It is strongly advised against driving a car with faulty piston rings. Damaged piston rings can harm the cylinder walls, which may lead to the failure of the entire engine block if left unaddressed.
Can bad piston rings cause hard starting?
Yes, worn piston rings can also make the engine hard to start during cold weather.
What does a broken piston ring sound like?
A damaged piston ring generates rattling or knocking noises while the engine operates. The distinct rattling sound caused by the damaged piston rings is difficult to overlook. This rattling noise will eventually be accompanied by engine knocking and misfires.
What are the signs of a faulty piston ring?
- Poor acceleration
- Oil leaks
- Poor oil economy
- Engine overheating
- Poor fuel economy
- Higher engine noise
- Poor vehicle performance
- Excessive exhaust smoke