Toyota Corolla Burning Oil – What Are the Causes?

It sounds like your Toyota Corolla may be experiencing some excessive oil consumption. Burning oil can happen for various reasons, and while youre not seeing visible smoke from the exhaust, its still something to pay attention to. Here are some potential causes and steps you can take to address the issue:
Common Causes of Oil Burning:

Worn Piston Rings: This is a common cause of oil burning, especially in higher-mileage vehicles. Worn piston rings allow oil to leak into the combustion chamber, where it gets burned off. Although this typically results in blue smoke from the exhaust, its still possible to have some oil burning without visible smoke.

Valve Seal Problems: The valve seals control the flow of oil into the combustion chamber. If theyre worn o r damaged, they can allow oil to leak into the engine and get burned. This may not always cause visible smoke but can still lead to excessive oil consumption.

PCV Valve Failure: The Positive Crankcase Ventilation PCV valve helps regulate engine pressure. If its clogged o r malfunctioning, it can draw excess oil into the intake manifold, leading to oil consumption.

Oil Leaks: Even small oil leaks that arent obvious can cause oil consumption. Check for any signs of oil around the engine, seals, o r gaskets.

What to Do:

Check for External Leaks: Look under the car and around the engine for signs of oil leakage. If you notice any, get the seals and gaskets checked and replaced if necessary.

Inspect the PCV Valve: Have a mechanic check the PCV valve to ensure its working properly. A malfunctioning valve can contribute to oil consumption.

Compression o r Leak-Down Test: To rule out issues with the piston rings o r valve seals, you might want to have a mechanic perform a compression o r leak-down test. These tests can help determine if there are internal engine issues causing the oil burning.

Oil Change and Proper Maintenance: Ensure that youre using the correct type and grade of oil for your Corolla. Sometimes, switching to a higher-viscosity oil can help reduce consumption, but its best to consult your owners manual o r a mechanic for advice on this.

When to Seek Professional Help:

If youre adding a quart of oil every few weeks, its a good idea to have a mechanic take a closer look. A thorough inspection can help pinpoint the cause of the issue. Ignoring it could lead to more serious engine damage down the road.

In summary, while burning oil isnt uncommon in older vehicles o r high-mileage engines, it’s important to identify the underlying cause early to prevent further damage. Consider getting a professional diagnosis to ensure your Corolla stays in good condition for longer.