Why Is My Car’s Engine Burning Oil? (& How To Fix It)

car burning or losing oil

When you put oil in your car, you expect the levels to remain the same until the next change, but that’s not always the case. In some instances, the oil levels might drop unexpectedly. When this happens, you want to know why your car is losing and burning oil.

In this article, we touch on why your oil levels might be dropping and whether it’s a normal circumstance happening with all vehicles. We also explain what you can do once you notice excessive oil consumption in your vehicle. 

6 Excessive Oil Consumption & Burning Reasons

1. Worn Seals or Gaskets

car oil leak

When the car has damaged or worn-out crankshaft seals or a valve cover gasket, it could be leaking oil. With this defect, oil is lost every time you drive, requiring you to top off the levels to keep the oil where it needs to be.

If you notice gaskets or seals that are worn out, you want to have them replaced immediately. In many cases, it can be quite inexpensive but helps you avoid costly engine repair later. Failed gaskets will lead to an external oil leak which should often be quite easy to locate if there is an oil pool under your car after you parked it.

2. Clogged crankcase ventilation

pcv valve

When the crankcase ventilation or the PCV valve is clogged, it can cause overpressure inside the crankcase which will push oil out of the motor through the sealings.

To fix it, locate the crankcase ventilation hoses and the PCV valve and make sure the air can move freely out from the engine. The crankcase ventilation does often have several hoses going to the engine, so it is important to check all of them.

RELATED: 7 Symptoms of a Bad PCV Valve

3. Poor or Wrong Oil Quality

car motor oil

Using the right type of oil is imperative for a well-running engine. Make sure you follow the manufacturer’s recommendations when choosing what oil to use.

Additionally, you want to change the oil regularly. When the oil becomes old and dirty, it can no longer lubricate the metal components inside the motor. This excessive friction is going to cause the engine to consume more oil. 

Check the engine oil to see what color it is. It should be tan or yellow-tinted. If it is black or dark brown, you have waited too long to perform an oil change, if you have a gas engine. Diesel engine oil will get black directly after a change. With an oil filter, drain pan, wrench and new oil, you can have it changed in twenty minutes. 

4. Defective Piston Rings

piston rings

When the piston rings become damaged or worn out, oil can seep through into the internal combustion chamber. Not only will this lead to oil burning, but carbon deposits can also start to form on the cylinders and piston rings.

You will notice the oil levels start to drop. However, the only solution to this problem is to replace the piston rings. 

RELATED: 4 Symptoms of a Bad Piston Ring

5. High Oil Pressure

With high oil pressure, the fluid floods through the engine in excess. When the oil falls into the cylinders, it is likely to burn up.

To solve this problem, you need to figure out what is causing the high oil pressure. The issue could be caused by a defect with the central computer or you might have added too much oil during the last service. 

6. Old, Worn-out Engine

During the first five years of an engine’s life, nothing major should go wrong. During these early years, oil shouldn’t be consumed excessively and you shouldn’t have to worry much about burning. 

Once the miles rack up, seals and gaskets start to break down and deteriorate. Small leaks can start and the engine will consume more oil. Additionally, an older engine might have bigger tolerances that permit oil to flow through spots that don’t exist with newer models. 

Is Burning Oil Considered Normal?

Oil burning is something commonly discussed among automotive owners, but manufacturers rarely provide information about the issue. Because of this, what might be considered a normal condition for one engine, could be considered excessive with the next. 

As an example, BMW informs drivers that some engines burn about a quart of oil within a thousand miles. Additionally, GM states that normal consumption is anything that is below a quart within 2,000 miles, as long as the vehicle is maintained and driven correctly. 

If your engine is using more than a quart of oil between the oil changes, it’s definitely something that should be looked at. 

How to Fix Excessive Oil Consumption

In general, a lot of the causes can be prevented simply by maintaining the vehicle and paying attention to any signs of trouble. You also want to make sure you are using the right oil type for your vehicle. Check the owner’s manual to make sure you have the right viscosity.

If you notice any leaks, you want to repair them as soon as possible. In many cases, replacing a gasket or seal won’t cost you a lot and can save you a lot of trouble. 

As the engine begins to age, you might want to upgrade to something newer before engine troubles set in. When you price the cost of replacing an engine versus the expense to upgrade, you will see the benefits. It’s best to sell your vehicle while it is still worth something, especially if you want to use the money as a down payment on something newer.

Written by:

Magnus is the owner and main author of MechanicBase. He has been working as a mechanic for over 10 years, and the majority of them specialized in advanced diagnostics and troubleshooting. He has also been a motorsport (drifting) driver for over 5 years.