Top 7 Reasons Why Cars May Burn Oil

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The most common reason for a car to burn oil is the age of the vehicle and its engine. Older vehicles and cars are more likely to burn more oil during operation when compared to newer vehicles. With age and time, the piston rings, seals, guides, and valves of the cars may wear out. The oil may start to move into the combustion chamber due to it. When the oil seeps through the other parts of the vehicle into the combustion chamber, it will start to burn in smaller amounts.

When a dipstick check shows a lesser than expected amount of oil, it may not be good for the health of the engine of the car. Oil, just like coolant, also circulates in a closed loop and circulation. Therefore, ideally there should be no loss of oil. However, you can check for the below-given issues when you find your car burning oil.

1. Leak in the Oil Gasket

The oil pan gasket is a large container made of metal. It can be found beneath the undercarriage of an automobile.

The pan gasket stores the engine oil when the car is stationary. Once the car starts to run, the oil is extracted and pulled from the pan by the engine. The oil remains secure in the pan due to a gasket.

Oil will start to leak when the gasket breaks down or when there is no air-tight seal.

2. Blown Gasket

The gasket or the head gasket separates the combustion gasses and the fluids so that they do not mix.

The engine oil may start to leak into the exhaust system or the cooling system of the car when the head gasket is worn out or is blown.

3. Worn/Damaged Valve Seals

The oil does not enter the car’s engine due to the presence of valve seals. If the seals are damaged or get worn out, the oil will flow into the cylinder of the car.

The oil will burn inside the engine and maybe later be released by the exhaust.

4. Just how the vehicle is

Some cars may burn more oil when compared to other cars during their operation and drive. For instance, cars from manufacturers including Honda and BMW burn a quarter of engine oil every 3000 miles.

5. Worn/Damaged Piston Rings

The piston rings seal and close the combustion chamber of the car’s engine so that other fluids (including engine oil) do not enter it.

However, when the piston rings are worn out or are damaged, the oil may enter the combustion chamber or the combustion gasses may start to escape from the engine.

6. Bad PCV Valve

Most cars have a PCV valve, which helps to remove fumes from the engine and prevent oil burning. If the PCV valve becomes clogged, it can cause oil to build up in the engine, leading to burning oil.

Symptoms of a bad PCV valve include blue smoke from the exhaust, oil leaks, and a decrease in engine performance. If you suspect that your PCV valve is faulty, it’s important to have it checked by a mechanic as soon as possible.

In the meantime, you can try to clean the valve by removing it and soaking it in solvent overnight.

7. It’s a rotary engine vehicle

Many people are surprised to learn that rotary engines actually burn oil by design. This is because rotary engines rely on a process called “oil metering” to lubricate the engine’s moving parts. In this process, oil is released into the engine at a controlled rate, and some of the oil is burned along with the fuel.

This may seem like a waste, but it is actually necessary for the engine to operate properly. The oil helps to keep the engine’s rotors cool and lubricated, and it also helps to seal the rotory chamber. As a result, without oil metering, a rotary engine would quickly overheat and fail.

The main vehicles in modern days that have rotary engines would be Mazda with the RX-7 and RX-8 being the most common.

Symptoms and resolution

When the car is burning oil and the fluid is being leaked into the combustion area and chamber of the vehicle, it is a serious problem. You may find smoke emanating out of the tailpipe of the car. It has to have a blue color tint.

Sometimes oil may burn without any blue tint in the smoke. In most cases, the problem may be solved through a simple car and engine tune-up procedure. In other cases, a deeper repair may be required.

Therefore, you should regularly check the car’s oil level. Also, ensure that the car is being serviced and maintained regularly. An expert car garage and mechanic has more resources and expertise in the area.

The experts can find out the issues and problems early on, and ensure that a major malfunction does not occur. A timely check will ensure that a sudden car breakdown or engine failure does not occur.

What is a normal amount of oil burned between oil changes?

Different vehicles and cars may burn the oil to different and varying extents. For instance, the BMW car manufacturer guidelines say that a quarter of the oil may be burnt by the vehicle in a thousand miles.

General Motors guidelines say that one-quarter of oil may be burned in 2000 miles. Some of the manufacturers may not comment anything on the issue.

If the engine of your car requires a quarter of oil for every 3000 miles (or in even lesser miles), there may be an oil leak. Sometimes the oil leak is not visible. It may occur due to the internal problems of a car engine.

As stated, the worn-out engine parts including piston rings, valves, guides, and seals may be a cause of the burn. A car that has run more than 75,000 miles may start to face the problem of excessive oil consumption. The problem will be more evident when the vehicle has covered more than 100,000 miles.


A well-serviced and regularly maintained car is less likely to suffer from problems such as excessive burning of engine oil.

There are multiple causes of the burning of oil. Not all of them can be diagnosed by common people.

While you can check for the oil levels in the car through a dip check, you should also ensure that the car is being serviced and maintained at a professional garage at optimum time intervals.

Timely efforts can provide you with a more reliable car that is free from issues such as oil burn.