5 Reasons Why Your Car is Burning Oil and What to Do About It

Burning oil can quickly cause serious problems to your car, like engine fires. And you may not even know it’s happening.

So how can you detect burning oil and prevent these problems? Keep reading.

Here are the 5 common causes of burning oil, how to detect them, and what to do about them. Check it out!

What Does “Burning Oil” Mean?

Engines are designed to keep the various engine liquids separate. If oil gets into the combustion chamber or other hot engine surfaces where it doesn’t belong, it burns.

This is actually two problems in one. First, your oil is leaking from somewhere. If your car runs out of oil, the engine starts grinding itself apart.

Second, the smoke from burning oil can destroy your expensive catalytic converter. It can also lower engine power, damage the environment and catch on fire.

How can you tell if your car is burning oil? If it goes through oil so fast it needs a refill in between oil changes, it’s losing oil somewhere. If your car isn’t leaving oil spots when parked, it’s burning up inside the engine.

Internal Oil Burning

Internal oil burning means oil is mixing together and burning with your fuel inside the engine. It happens mostly in older cars when the engine is wearing with age.

It may cause bluish smoke to emit from the tailpipe. But this will probably be blocked by the catalytic converter, so you may not see it.

If not taken care of right away, it could break your catalytic converter. Not to mention it’s a sign you need to replace one of several engine parts.

Here are a few causes of internal oil burning.

Cause #1: PCV System Malfunction

The positive crankcase ventilation (PCV) system is a system of one-way valves. It keeps fuel-air mixture from escaping the engine into the crankcase.

A blocked PCV valve can cause pressure in the crankcase. This can cause seals and gaskets to blow, which lets oil into the combustion chamber. There, it gets burned with the fuel.

Fortunately, the faulty PCV system parts can be replaced fairly easily and inexpensively.

Cause #2: Engine Intake and Exhaust Valves

As a car’s engine ages, the seals and guides of these valves can get worn out. When they fail, they let oil into the engine. If you see bluish smoke when you start your car or slow down quickly, this is probably the cause.

If you need the seals replaced, these aren’t too hard or expensive to replace. If it’s the guides… sorry. Your local mechanic will need to partially disassemble your engine.

It will cost a lot and you will be without a car for at least a couple days.

Cause #3: Worn Out Piston Rings

The piston rings are the seal between the cylinder bores and the pistons. They allow just enough oil in to lubricate the cylinders without letting too much oil into the cylinders.

When these wear out in old engines, they let excess oil into the cylinders. Once there, it burns with the fuel. If this is happening in your car, you may see the bluish smoke when you accelerate.

If worn out piston rings are the problem, the only feasible option is to look for a new car. It’s either that or a complete engine rebuild or replacement.

Oil on Hot Engine Surfaces

When the oil leaks onto hot engine surfaces, it can smoke or ignite inside your engine. To check this, run the engine at full power, lift the hood and look for smoke. Also, you’ll probably see new oil spots on the ground after you park.

If you see engine smoke or you’re losing oil very fast, don’t wait to get your car in. Small leaks are less urgent, but you still should take it in.

Here are the two main causes of external oil burning.

Cause #4: They Had One Job

Seriously, how hard is it to screw on the oil filter cap? About 90% of small oil leaks are due to loose cap or other negligence from a lazy oil change. Though you might lose oil too fast from this, it probably won’t spill onto the hot engine.

If you see oil dripping from the oil filter area, tighten the cap yourself or take it back in and make them do it.