Engine bearings play a critical role in the smooth operation of internal combustion engines. They support the rotating components of the engine, such as the crankshaft, and provide a smooth and low-friction interface between these components and the engine block.
The materials, design, and function of engine bearings can have a significant impact on engine performance, longevity, and efficiency.
In this article, we will dig into the various types of engine bearings, their functions, materials, and their importance in engine performance.
Engine bearing categories
In a car engine, there are several types of bearings. They perform different functions in the vehicle.
| Bearing Type | Function |
| Main Bearings | Support the crankshaft and ensure that it remains in the correct position within the engine block. |
| Connecting Rod Bearings | Support the connecting rods, which in turn connect the pistons to the crankshaft. |
| Camshaft Bearings | Provide support for the camshaft, which is responsible for opening and closing the engine’s valves. |
| Thrust Bearings | Maintain the position of the crankshaft and absorb any axial movement. |
| Journal Bearings | Support the shaft and provide a low-friction surface between it and the bearing surface. |
| Rod Bearings | Support the connecting rods and provide a low-friction surface between the rod and crankshaft. |
The image below shows how the engine Barings looks like.
How do engine bearings support engine performance?
Engine bearings in the car support the moving components of the internal combustion engine in different ways:
- Supporting The Rotating Components: Engine bearings support the weight of the crankshaft, camshaft, and connecting rods and maintain their proper position in the engine block.
- Absorbing Load And Vibration: Engine bearings absorb the load generated by the movement of the crankshaft, camshaft, and connecting rods, reducing friction and vibration.
- Reducing Friction: Engine bearings provide a low-friction surface between the moving components and the engine block, reducing heat and wear and improving engine efficiency.
- Maintaining Clearances: Engine bearings maintain a precise clearance between the moving components and the engine block, ensuring proper oil flow and reducing the risk of metal-to-metal contact.
What are the symptoms of a failing engine bearing?
As with any other car part, engine bearings are also subject to wear and tear over time. The below symptoms are some of the failing signs of the bearings.
- Engine Noise: A failing engine bearing can produce a knocking or ticking noise that increases with engine speed.
- Engine Vibration: A failing engine bearing can cause increased engine vibration, which can be felt through the steering wheel, pedals, or seat.
- Engine Oil Consumption: A failing engine bearing can cause increased oil consumption and lower oil pressure, leading to engine damage.
- Engine Misfire: A failing engine bearing can cause an engine to misfire, resulting in decreased engine performance and increased emissions.
- Engine Size: If a bearing fails completely, it can cause the component it supports to seize, resulting in engine damage and a loss of power.
If you notice any of the above signs, contact a professional mechanic to get it inspected.
What are the causes of engine bearing failures?
Overloading: If your car carries heavy loads or if the engine is operated at high speed for long periods of time regularly, the bearings can fail at an early stage.
Lack of Lubrication: Engine bearings need adequate lubrication to function properly. If the oil level is low, or if the oil is contaminated or not changed frequently enough, the bearings can fail.
Poor Quality Bearings: Engine bearings made with low quality materials can fail sooner.
Poor Installation: Engine bearings can fail if they are installed improperly, such as if they are not tightened to the proper torque specifications or if they are damaged during installation.
Wear and Tear: Engine bearings can fail as a result of normal wear and tear over time. This is why regular maintenance, including oil changes and engine inspections, is important to extend the life of the bearings.
How to select an engine bearing?
If you are wondering how to select good engine bearings, there are several factors to consider:
- Engine type and size: Engine be choosing the correct bearings for your engine is important it is important to choose the correct bearings for your engine.
- Load and Speed: Every engine bearing is designed to handle specific loads and speeds. Before you select a new bearing, make sure the new bearing has the capacity to keep up with the conditions under which the engine will be operated.
- Quality and Material: Engine bearings are made of various materials, including copper-lead, aluminum-tin, and tri-metal, and the quality of the bearings can impact their performance and longevity.
- Clearance: Engine bearings are designed with specific clearances to ensure proper oil flow and reduce the risk of metal-to-metal contact. It is important to choose bearings with the correct clearance for your engine.
- Engine Specifications: Engine specifications, such as the oil pressure and oil type, can impact the performance of engine bearings, so choose bearings that are compatible with your engine’s specifications.
Consulting with a professional mechanic or a reputable engine parts supplier can help you choose the correct engine bearings for your engine. Properly selecting and maintaining engine bearings is essential for ensuring optimal engine performance and longevity.
How to replace main bearings?
Replacing main bearings, which are pivotal in ensuring the smooth operation of the crankshaft within the engine, demands a methodical and precise approach. Here are the steps involved:
- Elevate the Vehicle: Safely lift and secure the vehicle to access the undercarriage.
- Remove Oil Pan and Pump: Detach the oil pan and oil pump to access the crankshaft.
- Detach Connecting Rods: Unbolt and remove the connecting rods from the crankshaft.
- Remove the Crankshaft: Carefully lift and remove the crankshaft from the engine block.
- Remove Old Bearings: Take out the old main bearings, noting their order and orientation.
- Install New Bearings: Place the new main bearings, ensuring correct positioning and applying lubricant.
- Reinstall Crankshaft: Place the crankshaft back, ensuring it rests securely on the new bearings.
- Reattach Connecting Rods: Reconnect the rods to the crankshaft, adhering to specific torque settings.
- Reinstall Oil Pump and Pan: Attach the oil pump and replace the oil pan to complete the process.
Given the intricate nature of replacing main bearings and the precision required, it is crucial to adhere to a detailed guide or manual specific to the vehicle model. The bearings ensure the crankshaft operates with minimal friction, promoting efficient engine performance and preventing premature wear.
Due to the complexity and the potential risk of engine damage if inaccurately performed, considering professional assistance for replacing main bearings is often advisable to safeguard the engine’s performance and longevity.
How to maintain the bearings in good condition?
Maintaining the bearings in good condition in a car is pivotal for ensuring smooth operation and prolonging the lifespan of various components. Here’s a step-by-step guide to maintaining bearings:
- Regular Inspection: Periodically check the bearings for wear, noise, or any signs of malfunction.
- Lubrication: Ensure bearings are adequately lubricated to minimize friction and prevent wear.
- Cleanliness: Keep the bearings and their surroundings clean to avoid dirt or debris, which can cause wear.
- Proper Installation: Ensure bearings are installed correctly to avoid misalignment or improper seating.
- Drive Carefully: Avoid driving through water or rough terrains that can stress or damage the bearings.
- Timely Replacement: Replace bearings at the first sign of wear or damage to prevent further issues.
- Use Quality Parts: Always opt for high-quality bearings to ensure durability and reliable performance.
- Professional Check: Have a professional mechanic inspect and service the bearings periodically.
Conclusion
This guide on engine bearings provides a thorough exploration of their crucial role in facilitating smooth engine operations, detailing various types, functions, and maintenance practices. The article adeptly navigates through the nuances of bearing selection, replacement, and upkeep, offering practical insights for both vehicle owners and mechanics. It also underscores the importance of recognizing and addressing bearing issues promptly to safeguard engine performance and longevity.
For more detailed guides and practical tips on car maintenance, explore further on the CarFinite blog.
John Smith, a Los Angeles-based car specialist and automotive writer, boasts over 20 years in the industry. With a background as a master technician and a decade-long writing stint at notable automotive publications, John now shares his expansive knowledge on CarFinite, simplifying car maintenance for readers.