How do you fix excessive oil consumption?

Excessive oil consumption is usually fixable by identifying the root cause and addressing it—often a worn engine component, a faulty PCV system, or leaks—and restoring proper lubrication with the correct oil and maintenance schedule.

Causes of excessive oil consumption

Understanding why oil is disappearing helps guide the right repair. The most common culprits fall into four broad categories: internal engine wear, PCV system faults, external leaks, and oil grade or handling issues.

• Worn piston rings or cylinder walls, which allow oil to enter the combustion chamber and burn off.


• Worn valve stem seals or guides, permitting oil to seep into the engine’s intake or combustion chamber.


• Faulty or clogged PCV (positive crankcase ventilation) system or breached breather circuit, which can pressurize the system and push oil into the intake or burn oil.


• External oil leaks from gaskets or seals (valve cover, oil pan, rear main seal, turbo seals on turbocharged engines).


• Turbocharger oil seals or bearings, if the vehicle is turbocharged, allowing oil to leak into the intake or exhaust.


• Incorrect oil grade or overfill, which can affect lubrication efficiency and sealing behavior.

In many vehicles, more than one issue can contribute to higher oil consumption. A careful diagnostic approach helps identify the dominant cause.

How to diagnose excessive oil consumption

Begin with a structured check to separate burning oil from leaking oil and to assess engine health.

1. Track oil usage by noting the amount added between oil changes and the distance driven; consumption above about 1 quart per 1,000 miles is generally considered excessive and warrants investigation.


2. Inspect for external leaks: check the undercarriage and around gaskets, seals, and hoses for oil drips or pools; inspect the valve cover and oil pan seals.


3. Check the PCV system: inspect the PCV valve and associated hoses for clogs or cracks; replace the valve if it sticks or clicks, and replace damaged hoses.


4. Observe exhaust smoke: blue smoke on startup or during acceleration suggests burning oil in the combustion chamber (often from worn rings or valve seals).


5. Perform a compression test and, if needed, a wet compression test to assess piston ring and cylinder health; a significant drop indicates wear that may cause oil burning.


6. Inspect the turbocharger (if equipped): look for oil in the intercooler, intake, or exhaust; test turbo seals and bearings for wear or leaks.


7. Evaluate oil condition: if the oil appears diluted with fuel or has unusual contaminants, investigate fuel system issues or improper combustion that could be contributing indirectly.

If you’re not comfortable performing these tests, a qualified technician can conduct them with diagnostic tools and service notes for your vehicle.

Repairs and remedies

Depending on the diagnosed cause, different fixes are appropriate. The following categories cover the most likely paths to resolving excessive oil consumption.

PCV system and leaks

When the PCV system or breathing circuit is at fault, address it with these steps:

• Replace a faulty PCV valve and any cracked or collapsed hoses or breather components.


• Clean or replace the oil separator or catch can if your system uses one, and ensure all vacuum lines are intact and free of leaks.


• Check for and repair any external oil leaks from valve covers, gaskets, or seals; reseal or replace components as needed.

Resolving PCV issues or leaks often reduces oil loss quickly and is typically less invasive than engine repairs.

Valve seals, guides, and related wear

If burning oil is traced to valve area wear, consider these actions:

• Valve stem seal replacement or repair of worn guides, which may require removing the cylinder head; maintenance varies by engine design.


• Inspect surrounding gaskets and seals for additional oil leakage; replace as needed.

Valve-related fixes can restore proper sealing, but may involve substantial labor on some engines.

Piston rings and engine wear

Excessive oil consumption due to ring or cylinder wear typically requires more extensive work:

• Perform a comprehensive engine diagnosis; if wear is confirmed, options include piston ring replacement or a full engine rebuild/replacement, depending on cost and vehicle value.


• Assess engine timing components and gaskets during the repair to ensure no secondary issues remain.

Oil consumption addressing wear is the most involved repair and is often a long-term solution rather than a quick fix.

External leaks and turbo seals

Leak-related fixes focus on sealing surfaces and, for turbocharged engines, possible turbo repairs:

• Replace faulty valve cover gaskets, oil pan gaskets, rear main seals, or turbo oil seals if applicable.


• Re-torque components to factory specs and ensure proper installation to prevent future leaks; inspect oil drain lines and feed lines for leaks.

Leaks are typically straightforward to fix and may dramatically reduce oil loss when addressed promptly.

Oil grade, viscosity, and maintenance practices

If the issue stems from oil choice or maintenance habits, consider:

• Switching to the manufacturer-recommended oil grade and viscosity; avoid using oil that is too thin or not specified for your engine.


• Ensuring the engine is not overfilled with oil after changes; correct oil capacity helps maintain proper pressure and seals.


• Adhering to the recommended oil-change interval and using high-quality oil that meets ACEA/ASTM specs for your vehicle.

Correct oil selection and proper maintenance can prevent future oil consumption issues, especially in engines prone to consumption with improper lubricants.

Prevention and maintenance

Preventive measures reduce the chance of oil consumption issues returning. Use these practices to keep engines healthy over time.

• Always use the oil grade and viscosity specified by the manufacturer and avoid overfilling during changes.


• Regularly inspect and replace the PCV valve and hoses; clean or replace the oil separator as part of routine maintenance.


• Check for and fix any oil leaks promptly, including valve covers, oil pans, and seals; address turbo seals if applicable.


• Maintain proper air intake and fuel systems to prevent excessive carbon build-up, which can influence oil usage indirectly.


• Monitor oil level between changes and keep a log of consumption to catch trends early.

Proactive maintenance reduces the likelihood of unexpected oil loss and helps protect engine life.

When to seek professional help

Some symptoms require professional evaluation and specialized tools.

• Blue or white smoke from the exhaust and rising oil consumption warrants inspection for burning oil due to internal wear.


• Visible oil leaks, puddles under the vehicle, or oil smell inside the cabin are signs to stop driving and have the vehicle inspected.


• Low compression or abnormal leak-down test results indicate internal engine wear that may require targeted repairs or a rebuild.


• If your vehicle is under warranty or affected by a service bulletin related to oil consumption, contact the dealership for guidance and potential coverage.

Timely professional help can prevent further damage and help determine the most cost-effective repair path.

Summary

Excessive oil consumption is a common issue with several possible causes, most often including PCV system faults, valve or piston wear, external leaks, or incorrect oil practices. A structured approach—start with simple checks (oil grade, leaks, PCV), measure consumption, perform compression tests if needed, and then pursue targeted repairs—will usually identify the culprit. Many cases are resolved with relatively straightforward fixes (PCV replacement, sealing leaks, or valve work), while others may require more extensive engine repair. Regular maintenance and using the correct oil are key to preventing recurrence.

Is it worth fixing a car that burns oil?

First of all, if your vehicle is burning up a lot of oil often, it could be a serious problem. If you're not in a position to pay out huge repair bills, you might be better off cashing in on your car and selling it as scrap or salvage with Scrap Car Comparison.

What are the two main causes of excessive oil consumption?

THE CAUSES OF EXCESSIVE OIL CONSUMPTION

• IMPROPER OR POOR-QUALITY OIL. Different engines require the use of specific lubricant blends.
• DAMAGED PISTON RINGS.
• OLD ENGINES.
• WORN SEALS OR GASKETS.
• BLUE SMOKE.
• LOW COMPRESSION.
• HIGH-CARBON FORMATION IN THE ENGINE.
• COOLANT DETERIORATION.

How to stop excessive oil consumption?

To fix oil consumption, first try simpler solutions like using the correct oil grade and changing it at recommended intervals, and replacing the PCV valve. If these don't work, you can use an engine flush to clean deposits on piston rings and valve seals before an oil change, or try a "motor oil saver" additive to help restore seals. For severe cases, mechanical repairs like replacing piston rings, valve seals, or head gaskets may be necessary. 
Initial and less invasive fixes
This video explains the common causes of oil consumption and initial fixes like checking oil quality: 1mMechanic BaseYouTube · Oct 22, 2024

• Use the correct oil: Ensure you are using the oil viscosity and type recommended by your vehicle's manufacturer. Using a different grade can affect consumption. 
• Regular oil changes: Follow your manufacturer's maintenance schedule and change your oil at the recommended intervals. 
• Replace the PCV valve: A clogged or faulty PCV valve can increase crankcase pressure and lead to oil consumption, so inspect and replace it. 
• Check for leaks: Regularly inspect for any external oil leaks by looking for oil spots on the ground or a strong oil smell. 

Intermediate fixes
This video demonstrates how to use a piston soak to clean the rings: 57sBucket of BoltsYouTube · Dec 15, 2023

• Use an engine flush: Before an oil change, use an engine flush product to clean out sludge and deposits that can clog piston rings and valve seals. 
• Use an oil additive: Products like "motor oil savers" can be added to the oil to help condition and swell old, brittle seals to reduce leaks. 
• Consider higher mileage oil: Some high-mileage oils contain additives that help clean the engine and condition seals. 

Severe cases and mechanical repairs 

• Engine flush with multiple oil changes: Some mechanics suggest doing an engine flush followed by several short-interval oil changes to ensure the cleaning agents are completely removed. 
• Mechanical repairs: If the above methods don't work, the issue is likely due to worn-out internal parts. This may require a professional to fix and can be expensive. 
  • Piston rings: Worn or stuck piston rings are a common cause of oil burning and require opening up the engine for replacement. 
  • Valve seals: Worn valve stem seals can also cause oil to be burned. In many cases, these can be replaced without removing the entire engine. 
  • Head gasket: A blown head gasket can lead to oil and coolant leaks, and replacing it is a necessary repair. 

What can I put in my engine to stop it burning oil?

Treating an oil-burning engine can involve using oil additives to clean deposits, using thicker oil, or performing more involved engine repairs like a piston ring or valve job. Additives can help restore performance by cleaning internal engine parts, while a thicker oil may temporarily reduce consumption. For a lasting solution, particularly in older engines, major repairs may be necessary. 
Short-term or minor treatments
This video demonstrates how to diagnose an oil burning engine: 1mScotty KilmerYouTube · Oct 31, 2023

• Use engine oil additives: Products like Sea Foam, Bardahl, or Lucas Oil are designed to clean carbon deposits, which can restore the ability of piston rings to seal properly. These can be added to the engine oil or fuel. 
• Use a piston soak treatment: A special detergent can be poured into the engine, which is then idled to clean carbon deposits from the pistons and rings. 
• Switch to a thicker oil: Using the heaviest weight of oil recommended for your engine can help reduce oil consumption, though this is not a permanent fix. 

Long-term or major repairs
You can watch this video to learn how to perform a BG service on a car that is burning oil: 52sDeutsche Auto PartsYouTube · May 19, 2022

• Perform a valve job and/or ring job: For significant oil burning, the only way to fix the issue is to rebuild the engine. This may involve replacing the piston rings or performing a valve job.
• Replace the engine: In severe cases, especially in older vehicles, replacing the engine may be more cost-effective than a full rebuild. 

Important considerations

• Consult a professional: It is best to have a mechanic diagnose the cause of the oil burning to determine the appropriate course of action.
• Monitor oil levels: Regardless of the treatment, it is crucial to check your oil level frequently and add oil as needed to prevent engine damage. 
• Understand limitations: Additives may not be a permanent fix and might not work for severely worn engines.