Several car components play a crucial role in the engine’s functioning. Piston rings are such components that create a seal between the piston and cylinder wall. This seal is crucial for optimising engine performance by maintaining an accurate compression ratio and preventing loss of power.

Here are all the details about rings on the pistons, their working and function, types, materials and symptoms of bad rings.

The Function of Piston Rings

The primary function of piston rings is to create a tight seal between the piston and the cylinder wall. They are circular metal rings installed around the outer diameter of the pistons. Here are the main functions of piston rings:

• The piston rings ensure that the compressed gases do not leak past the piston and escape into the crankcase, maintaining high pressure and promoting efficient combustion.
• They prevent excessive engine oil from entering the combustion chamber and being burned with the air-fuel mixture. 
• These act as heat conductors to transfer heat from the piston to the cylinder wall and dissipate it into the different engine’s cooling system types.
• The rings help stabilise the pistons while moving up and down in the cylinder to prevent excessive vibration and ensure smooth engine operation.

The functions of piston rings depend upon the types and their material. Let’s find out all the details.

Material of Piston Rings

Piston rings are typically made from durable and heat-resistant materials to meet the demanding engine operation requirements. The most common materials used for rings include:

• Cast Iron
• Steel
• Compression-Molded Graphite
• Chromium
• Molybdenum
• Ceramic

Types of Piston Rings

Here are the following types of rings on the piston, and both serve a certain purpose:

Compression Rings

This type of piston ring is the top ring on the piston and serves the crucial function of sealing the combustion chamber. Their primary role is to prevent the high-pressure gases generated during the combustion process from leaking past the piston and into the crankcase. By ensuring a tight seal between the piston and the cylinder wall, compression rings contribute to the engine’s overall power and efficiency.

Oil Control Rings

The oil control rings regulate the amount of oil on the cylinder walls. They are positioned below the compression rings and perform two essential functions. 

First, the scraper ring, the top ring in the oil control ring set, scrapes excess oil from the cylinder walls during the piston’s downward stroke, returning it to the oil pan. Second, the oil ring expander or oil wiper ring, located below the scraper ring, helps to control the oil film left on the cylinder walls and ensures proper lubrication without allowing excessive oil into the combustion chamber.

Symptoms of Damaged Piston Rings

Damaged piston rings can lead to several symptoms in an internal combustion engine. The rings are crucial components that help maintain compression within the combustion chamber and prevent the leakage of gases. When they malfunction, it can cause various issues that may affect the engine’s performance. 

Some common symptoms of failed piston rings include:

Reduced Engine Compression

Damaged piston rings can result in decreased compression in the cylinders. That said, it results in loss of power and reduced engine performance. It is also a symptom of piston damage.

Increased Oil Consumption

When rings are worn, they may fail to seal the combustion chamber. It can cause oil to leak into the combustion chamber and get burned along with the fuel, becoming a cause of increased oil consumption.

Blueish-Grey Exhaust Smoke

Excessive oil consumption due to damaged piston rings can result in blueish-grey car exhaust smoke. It is a sign of burning oil alongside fuel in the combustion process.

Poor Acceleration

Reduced compression and power output can be one of the reasons for sluggish acceleration and poor engine response, especially during acceleration or under load.

Rough Idling

Rough engine idling or stalling can happen due to inconsistent compression levels caused by faulty piston rings.

Overheating

If the rings malfunction, the decreased compression and power output can cause the engine to work harder. It will lead to increased heat generation and become a potential cause of car engine overheating.

Piston Ring Installation Instructions

When the piston rings wear out, here’s how to install the new ones to avoid the drop in engine performance.

• Clean the pistons and grooves thoroughly to remove any traces of the old rings and carbon buildup.
• Check the new rings for any defects and ensure they are the correct size and type for your engine. 
• Coat the new rings with engine oil or assembly lubricant. 
• Start with the bottom compression ring. Carefully insert it into the groove, ensuring it sits flat and level.
• If you have an oil control ring with expanders, install the expander first into the lower groove and then the upper groove. Ensure that the expander ends meet but do not overlap.
• Install the top compression ring into its respective groove.
• Place the piston and rings into a compressor tool.
• Once the piston is in the cylinder bore, ensure that the ring gaps are still correctly positioned as per the manufacturer’s specifications. You can use a feeler gauge to check the gaps.

It is a wrap to the comprehensive information about car piston rings. Although it is a small component, it plays a vital role in the engine’s performance and power. When buying a used car for sale in the UAE, ensure all components are working properly to achieve efficient car performance.

Stay tuned to the dubizzle cars blog to learn more about auto parts, their functions and symptoms.