Everything You Need to Know About Engine Oil: Questions Answered
Engine oil is one of the most critical components of a vehicle, performing crucial functions, yet it often raises many questions among drivers. From understanding its purpose to addressing common concerns, this blog post will cover everything you need to know about engine oil to keep your car in top condition.
What Does Engine Oil Do?
It may seem obvious but understanding the role of engine oil highlights why using the right oil and maintaining regular changes is essential for your car’s health. Engine oil has several key functions:
- Lubrication: It forms a protective layer between moving parts, such as pistons, bearings, and camshafts, reducing friction and preventing wear.
- Cooling: By dissipating heat generated from engine friction, oil helps maintain optimal operating temperatures.
- Cleaning: As oil circulates, it picks up dirt, debris, and combustion by products, keeping the engine clean and efficient.
- Sealing: Oil seals small gaps, such as between piston rings and cylinder walls, maintaining compression and preventing leakage.
- Corrosion Protection: Additives in oil protect metal surfaces from rust and corrosion, especially during periods of inactivity.
Using the right grade of oil, such as 5W-30 or 10W-40, ensures proper lubrication and performance across a range of temperatures. Regular oil changes are crucial to maintaining these benefits.
Types of Engine Oil
There are three main types of engine oil:
Fully Synthetic: Offers the best protection and performance, especially for high-performance engines.
Synthetic Blend: Provides a balance between performance and cost.
Conventional: Suitable for older vehicles and those with simple engine designs.
High-mileage oils are also available, specifically formulated for vehicles with over 75,000 miles.
Common Questions About Engine Oil
Can Engine Oil Expire or Go Out of Date?
Yes, engine oil can expire. Over time, its additives break down, reducing its effectiveness. Unused engine oil typically has a shelf life of 5 years. Once opened, it’s best used within 2-3 years. However, some synthetic and semi synthetic oils can last even longer, up to 7 or 8 years. Store your engine oil in a cool, dry place between 40-85 degrees Fahrenheit (4-29 degrees Celsius). Oil will degrade when exposed to air, heat, light and water. Always check the expiry date on the packaging and avoid using old oil.
Can Engine Oil Catch Fire?
Engine oil is flammable under extreme heat but has a high flashpoint, making it safe for use in engines under normal conditions.
Can Engine Oil Freeze?
While engine oil doesn’t freeze solid like water, it can thicken in extremely cold temperatures, but rarely fully freezes. Using the correct oil viscosity for your countries climate is essential to prevent this. This is why multi-grade oils are design to maintain a proper viscosity across a wide temperature range.
Can Engine Oil Expire?
Yes, Check the manufacturer’s guidelines for specific storage recommendations.
Can Engine Oil Be Mixed?
Mixing oils of different grades or brands is not recommended, as it can compromise the oil’s performance. Always use oil that meets your car manufacturer’s specifications.
Which Engine Oil Is Best?
The best engine oil depends on your car’s make, model, and age, therefore depends on your cars manufacturers recommendations. Also consider your local climate, mileage and driving conditions. You can use an oil finder but it’s best to check your owner’s manual.
What Engine Oil Do I Need?
Refer to your car’s manual or ask a professional to determine the right oil grade and type for your vehicle.
Common viscosity grades include 5W-30, 10W-40, and 0W-20. The first number indicates cold-temperature performance, while the second number represents high-temperature viscosity.
Engine Oil is Low Sign
Common signs include the oil warning light on your dashboard, a noisy engine, or poor performance.
What Happens if the Engine Runs Without Oil?
Driving without oil can cause catastrophic damage, leading to engine failure and expensive repairs.
Engine Oil vs Transmission Oil
Engine oil lubricates and cools the engine, while transmission oil serves the gearbox. They are not interchangeable.
Engine Oil Capacity
The engine oil capacity varies depending on your car’s make and model. Most passenger cars require between 4 to 8 litres of oil, while larger vehicles, such as trucks, may need more. To find the exact capacity for your vehicle, check the owner’s manual or consult a professional mechanic.
Engine Oil Cleaner
An engine oil cleaner is an additive designed to remove sludge, deposits, and contaminants that build up in your engine over time. These cleaners help restore engine performance, improve fuel efficiency, and prepare the system for fresh oil during an oil change. They are typically used as part of a pre-oil change flush to maintain engine health.
Engine Oil Operating Temperature
Engine oil operates most efficiently at temperatures between 90°C and 105°C (194°F to 221°F). Maintaining this temperature range ensures proper lubrication, reduces wear and tear, and supports optimal engine performance. Exceeding or falling below this range can lead to reduced oil effectiveness and potential engine damage.
Engine Oil Remover
An engine oil remover is a product or tool used to clean up oil spills or leaks. For driveway or garage spills, specialised oil absorbent powders or degreasers are effective at breaking down and removing oil stains. For your engine, professional tools like an oil extractor pump can safely remove old oil during servicing. Always dispose of used oil responsibly in accordance with local regulations.
What Happens When Oil Gets Old?
As oil picks up dirt and debris, it degrades over time, becoming thick and less effective at lubricating the engine. Neglecting regular oil changes can lead to:
- Increased engine wear and tear.
- Formation of sludge, which restricts oil flow.
- Engine seizure, potentially costing upwards of £5,000 to replace.
Shockingly, 8 out of 10 drivers don’t know how often their oil should be changed, and a third of drivers delay servicing to save money. Regular servicing and oil changes are crucial to avoid costly repairs.
Engine Oil-Related Issues and Tips
Burning Engine Oil
Burning oil may result in blue smoke from the exhaust or a strong burning smell. This could indicate a leak or worn piston rings.
Oil Light Flashing or On
A flashing or illuminated oil light means your oil level or pressure is low. Address this immediately to avoid damage.
Mixing Oil with Coolant
This could be a sign of a blown head gasket, requiring urgent attention from a mechanic. A sign of oil mixing with coolant is the fluid in your coolant reservoir turns a dark colour potentially fully black depending on how severe the leak.
Oil Colour
New oil is amber in colour, but unless it is new from factory there will be residue left from the previous oil which will turn the new oil a dark black colour once started. Just because your oil is dark in colour doesn’t always mean it needs to be changed. If your oil is a milky white colour that is a possible indicator of oil dilution, make sure to take your car to a trusted garage to find the definite source of the issue. Driving for an extended period with discoloured oil is not advised. If your oil seems to be sparkly or glittery but still black seek advice from a trusted mechanic immediately.
Checking Oil Levels
Use your car’s dipstick to check the oil level regularly. Ensure the oil is between the minimum and maximum markers.
The Importance of Regular Oil Changes
Regular oil changes are essential for maintaining your car’s health. During an oil and filter change, your mechanic will replace old, contaminated oil and the oil filter, ensuring the engine operates efficiently. This helps:
- Prolong engine life.
- Improve fuel efficiency.
- Reduce emissions.
Maintenance and Monitoring
How to check engine oil:
- Park on level ground
- Wait 5 minutes after engine shutdown
- Remove dipstick (it’s location will be in your vehicle manual), wipe clean
- Reinsert fully and remove
- Check oil level between MIN and MAX marks
- Note oil colour
Warning Signs to Watch For:
- Oil pressure warning light
- Burning smell
- Engine knocking sounds
- Oil spots on driveway
- Mixed oil and coolant
If your engine oil is low this can cause severe engine damage, potentially leading to complete engine failure.
Oil Change Basics
Low Oil Pressure:
- Check oil level
- Inspect for leaks
Important Safety Tips
- Never mix different oil weights or types unless specifically approved
- Maintain proper oil levels to prevent engine damage
- Address oil leaks promptly
- Keep maintenance records
- Follow manufacturer recommendations
Popular Oil Questions Simplified
- Engine Oil Grades: Indicates the oil’s viscosity (the thickness of the oil). Common grades include 5W-30 and 10W-40.
- Engine Flush: Additives designed to remove sludge and debris from the engine.
- Engine Oil Capacity: Check your owner’s manual for the exact capacity needed for your car.
- Engine Oil Pressure Low: A common fault that could indicate a leak, pump issue, or low oil level.
Remember: A new engine would be a huge cost! Regular oil changes are far less expensive than engine repairs and so proper maintenance is crucial for keeping your vehicle running smoothly, efficiently, extending your engine’s life and improving it’s performance.
Keeping Your Car Roadworthy with Bartlett Automotive
At Bartlett Automotive, we provide expert oil and filter changes as part of our comprehensive car servicing. Our skilled technicians can help you select the right oil for your vehicle and ensure all components are running smoothly. Whether you’re dealing with BMW timing chain issues, an oil pressure fault, or just need routine maintenance, we’re here to help.
Visit our Huntingdon or Peterborough branches for quality service and advice. Don’t wait for an oil-related issue to disrupt your drive—schedule your service today!
