The engine oil is very important to maintain the good health and efficient performance of the engine. It plays a vital role in lubricating moving components, minimizing friction, preventing the engine from overheating, and also helps to prevent contaminants from damaging the engine. If the engine oil level in your car drops unexpectedly, there are typically two potential reasons: an oil leak or oil burning within the engine.
If your car is consuming oil rapidly and you also notice an oil burning smell or blue smoke from the exhaust, that’s not good. This occurrence usually signifies that your vehicle is burning oil while running, which can lead to big and expensive problems to fix. This article mainly explains the car burning oil causes and symptoms.
How Do I Know My Car Is Burning Oil?
If the engine of your car is burning oil, you might often see the engine oil light turning on. When you check the oil level using the dipstick under the hood, you might also notice that it’s consistently going down.
- Blue smoke coming from the tailpipe: If you see blue smoke, it might mean that the oil is burning in the engine while it’s running.
- Poor Engine Performance: Reduced engine power, poor fuel economy, and poor acceleration, all represent insufficient oil.
- Smell of burning oil: When your car burns oil, you may notice a strong smell of burning oil.
- Overheating: The main purpose of the engine oil is to ensure the normal operating temperature of the engine parts. When your oil burns in the combustion chamber, there will not be sufficient oil to cool the engine parts, causing overheating issues.
- Low oil warning light: If the low oil light keeps coming on, it could suggest your car is using up too much oil or burning it.
Why Causes a Car Engine To Burn Oil?
A bad PCV valve, a blown head gasket, clogged crankcase ventilation, damaged piston rings or use of wrong oil are the most common causes that may force your car to burn more oil.
Let’s discuss the main causes of why is oil burning in the car engine:
1) Clogged Crankcase Ventilation
The crankcase is the area where the engine oil is stored, along with the crankshaft. When the engine operates, the piston creates exhaust gases, which build up pressure. These gases are directed back into the engine cylinder using the PCV valve.
Your engine combines these combustion gases with the air/fuel mixture for burning. But if the crankcase ventilation is blocked due to issues like a damaged breather hose or clogged valve covers, the gases can’t be released as they should.
This situation causes an issue called oil blowback, where oil enters the combustion chamber instead of fuel. This leads to the engine using up oil quickly.
2) Oil Filter Cap Leak
The oil filter cap is responsible for covering the engine’s fill opening. However, when this cap is damaged, it may lead to engine oil spilling onto the engine’s surface, causing it to burn in the engine.
3) Bad PCV Valve
The PCV valve of your car plays a vital role in redirecting the hazardous exhaust gases into the engine cylinder for a second burn before they are expelled into the environment. However, it may become blocked or become faulty over time.
As the PCV valve becomes faulty, it leads to oil blowback. Oil is drawn into the combustion chamber and starts burning. Consequently, you might see blue smoke emitting from the exhaust pipe.
Read More: Bad PCV Valve Symptoms and Causes
4) Poor Quality Oil
Using low-quality or wrong oil can be a simple issue to fix. If the oil you’re using can’t handle high temperatures, it might not be giving your engine the protection it requires.
Regular oils, especially conventional ones, can break down easily when exposed to excessive heat. This not only reduces the level of your oil but also speeds up the accumulation of carbon within your engine, which is very harmful to your engine parts.
If you add the wrong viscosity oil to your engine, it may also harm your vehicle. If the oil isn’t according to the manufacturer’s recommendations, it might be too thin. Thin oil may seep through worn-out rings or valve seals more easily compared to high-viscosity oils.
This is why it’s crucial to follow the specific oil type recommended by your car’s manufacturer, which you can find in your vehicle’s service manual.
5) Damaged Gaskets or Seals
A faulty gasket or seal is one of the major causes of oil burning in the combustion chamber. When the internal gaskets or seals break, the oil may start to leak into the combustion chamber. Such internal leakage is hard to spot. When the oil burns, you may notice blue smoke coming from the tailpipe.
Alternatively, when the head gasket is blown, you might be losing oil, but you won’t see any obvious leaks. Yet, if you inspect the coolant reservoir, you might notice that oil has mixed with the coolant. A blown head gasket may also cause engine overheating and often requires expensive repairs.
Read More: Blown Head Gasket Symptoms and Causes
6) Excessive Oil Pressure
Ensuring sufficient oil pressure within your engine is important to lubricate its parts properly. Any blockages may cause higher oil pressure, which in turn can cause higher consumption of the engine oil.
For instance, a potential culprit could be a clogged oil filter in your car. Replacing the clogged oil filter may restore normal oil flow and contribute to maintaining optimal engine temperature.
7) Faulty Piston or Piston Rings
A faulty piston or piston ring may also lead to an oil leak into the combustion chamber where it burns. The piston ring has the responsibility to produce a tight seal against the walls of the engine cylinder. This seal is crucial for preventing combustion gases from escaping and ensuring proper engine compression.
As the cylinder walls get damaged, or piston rings wear out, oil may get into the combustion chamber. This oil gets burned up, and you’ll notice that your oil level goes down between oil changes. This problem also results in poor engine performance, engine stalling, sluggish acceleration, or more exhaust smoke.
Read More: Bad Piston Ring Symptoms and Causes
8) Worn Engine Parts
For older vehicles with substantial mileage, it’s possible that the internal components of the engine have worn out over time. The vehicle’s engine has a limited lifespan and isn’t meant to last indefinitely.
Even if you take necessary control measures to maintain the engine’s performance, it will ultimately reach a point of failure. When the condition of your engine worsens, you’ll observe increased oil consumption.
9) Bad Valve Seals
Your engine valves contain a seal. This valve stem seal serves an important function in regulating oil within the valve guides and maintaining the oil consumption rate. But in the case of faulty valve stem seals, the circumstances can take a negative turn. This can be apparent as a clear reduction in oil levels.
When the valve stem seal is compromised, it can allow oil to seep inside the engine cylinder. This can result in the emission of blue smoke from the exhaust. Moreover, insufficient oil levels can potentially lead to the complete failure of the engine.
How to Fix Excessive Oil Consumption
If your car is burning oil more than a specified limit, follow the below-given steps to fix it. Firstly, you need to locate the main issue. Follow the following to fix excessive oil consumption.
- Inspect the oil level and add more oil if needed. Follow the recommended oil change interval.
- Check the oil color. If it looks dirty, flush it and add new oil.
- Check the oil viscosity. You should use an oil recommended by your owner’s manual.
- Properly examine the crankcase ventilation. If it is clogged, clean it properly. If it is damaged, it is compulsory to replace it.
- Inspect the PCV valve. If it is damaged, replace it.
- Inspect the oil filter. If it is clogged, properly clean it.
- Inspect the piston and piston rings. If any of these parts are damaged, it is recommended to replace them promptly.
- Inspect the valve stem seal and head gasket. If they are damaged, replace them promptly.
- If you are unable to find the main cause of excessive oil burning, it is recommended to consult a professional.
How Much Does It Cost to Fix a Car That’s Burning Oil?
If your car burning excessive oil, it is recommended to fix the issue as soon as possible to ensure the smooth operation of your car. The fixing cost of the burning oil depends on the relevant faulty part and labor costs. Following are some estimated costs:
| Parts | Cost |
|---|---|
| Piston rings replacement | $900 to $5200 |
| Head gasket replacement | $1,000 to $2,100 |
| PCV valve replacement | $180 to $250 |
FAQ Section
How long can an engine last with burning oil?
The outcome isn’t predictable. Some vehicles might burn a bit of oil and continue running fine as long as you keep refilling the oil. While in many vehicles, the engine may experience premature failure if the issue isn’t fixed. Therefore, it is crucial to promptly find and address the problem to prevent potential long-term damage.
Can I drive with burning oil?
Technically, you can drive with burning oil, but it is not recommended. When the engine oil burns, its level reduces very quickly. Moreover, if you don’t consistently maintain the oil level and it becomes lower than a specified limit, it may lead to the failure of the engine parts. Eventually, this might lead to the need for a costly engine rebuild or replacement, which could have been avoided by addressing the main issue.
Can a car burning oil fail emission tests?
Yes, if your vehicle is burning excessive oil, it may be unable to pass the emission test.
Can high-mileage oil stop burning oil?
If the engine of your car contains a substantial number of miles, changing the type of oil you use could be beneficial. This special oil is great for older engines because it protects them well, reducing the amount of oil burned between oil changes. It’s crucial to ensure that your engine oil viscosity matches the manufacturer’s recommendation, and you can find this info in the owner’s manual.
How much oil burn is normal?
Most automakers think it’s okay if a car burns around one quart of oil within approximately 1,500 miles. It’s worth noting that certain high-performance vehicle models might burn a quart of oil in fewer than 1,000 miles, but that’s still okay for those types of cars.
Why is my car losing oil but no leak or smoke?
If the engine level in your vehicle is reducing more quickly than usual, but there are no visible oil leaks, it is possible that your oil is leaking in the combustion chamber where it’s burning.
Why does my car produce a burning oil smell?
If your car is making a burning oil smell, it means that your oil is burning or it is leaking.
How long should oil last in a car?
Even with the impressive progress in oil technology and engine design, it remains advisable to change oil approximately every 3,000 miles (4,500 kilometers). Many automakers even suggest getting it done between 7,500 to 10,000 miles (11,000 to 15,000 kilometers), as mentioned in their manuals.
Does oil affect car speed?
Over time, your engine oil starts to degrade, losing its effectiveness and causing increased friction and heat between the moving parts of the engine. This added strain on your engine can result in reduced engine power, decreased acceleration, and other performance-related concerns.
How to stop oil burning in engine?
- Check your engine oil regularly
- Regularly inspect your system for leaks
- Always use the recommended oil grade
- Follow the recommended oil change interval
- Avoid aggressive driving
- Avoid excessive idling