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2017 Subaru Impreza Burning Oil: Causes & Fixes

By ClearTheCode · Published 2026-05-31 · ~6 min read

Experiencing 2017 Subaru Impreza burning oil? Learn common causes, how to diagnose, and effective fixes to stop excessive oil consumption and protect your engine.

At a glance

Difficulty
6/10 — Easy to moderate
Est. repair cost
$100 – $800 (parts + typical shop labor)
OEM tooling
Standard OBD-II scanner and hand tools
Common symptoms
  • Decreased fuel economy: Oil burning can affect engine efficiency.
  • Reduced engine performance: A fouled engine may not run as smoothly or powerfully.
  • Carbon buildup on exhaust tips: A black
  • oily residue on the tailpipe can indicate oil burning.
  • Oil leaks: While not always the cause of *burning* oil
  • external leaks can contribute to low oil levels and should be ru

Is your 2017 Subaru Impreza demanding frequent oil top-ups between its scheduled service intervals? If you're consistently adding a quart or more every few thousand miles, you're likely dealing with excessive oil consumption, a known concern for some owners of this model year. This issue goes beyond typical engine wear and can lead to serious long-term damage if not addressed.

What drivers notice on this 2017 Subaru Impreza

Drivers with a 2017 Subaru Impreza experiencing excessive oil consumption typically notice several tell-tale signs:

  • Frequent oil top-ups: The most common indicator is having to add a quart or more of engine oil every 1,000 to 3,000 miles, significantly more often than expected.
  • Low oil warning light: The oil pressure or level warning light may illuminate on the dashboard, especially during turns or hard braking, indicating a critically low oil level.
  • Blue smoke from exhaust: Particularly noticeable during startup, acceleration, or after prolonged idling, blue-tinted smoke suggests oil is being burned in the combustion chambers.
  • Burning oil smell: A distinct odor of burning oil may be present, often coming through the vents into the cabin.
  • Engine noise: In severe cases where oil levels drop too low, you might hear unusual engine noises like ticking or knocking due to inadequate lubrication.
  • Spark plug fouling: Oil burning can lead to carbon buildup on spark plugs, potentially causing misfires, rough idling, or reduced fuel economy.

At a glance: difficulty, repair cost, and diagnostic workflow

  • Difficulty Rating: 6/10 — Easy to moderate
  • Common Symptoms: Decreased fuel economy: Oil burning can affect engine efficiency.; Reduced engine performance: A fouled engine may not run as smoothly or powerfully.; Carbon buildup on exhaust tips: A black, oily residue on the tailpipe can indicate oil burning.; Oil leaks: While not always the cause of burning oil, external leaks can contribute to low oil levels and should be ru
  • Estimated Repair Cost: $100–$800 (parts + typical shop labor)
  • OEM Tooling Required: Standard OBD-II scanner and hand tools

Diagnostic workflow:

  1. Confirm the symptom on your vehicle.
  2. Scan for stored or pending codes with an OBD-II tool.
  3. Inspect the most common causes in this guide (visual checks first).
  4. Run verification tests before replacing parts.
  5. Repair, clear codes, and verify on a test drive.

Symptoms and warning signs

Beyond the primary symptom of needing to add oil constantly, watch out for these specific signs in your 2017 Subaru Impreza:

  • Decreased fuel economy: Oil burning can affect engine efficiency.
  • Reduced engine performance: A fouled engine may not run as smoothly or powerfully.
  • Carbon buildup on exhaust tips: A black, oily residue on the tailpipe can indicate oil burning.
  • Oil leaks: While not always the cause of burning oil, external leaks can contribute to low oil levels and should be ruled out.

How to verify and confirm the issue

Confirming excessive oil consumption in your 2017 Subaru Impreza requires careful monitoring and observation:

  • Establish a baseline: Top off your engine oil to the full mark on the dipstick. Note the mileage.
  • Regular dipstick checks: Check your oil level every 500-1,000 miles. Keep a detailed log of mileage and how much oil you add each time. This is crucial for quantifying consumption.
  • Visual inspection for leaks: Park your Impreza on a clean, dry surface. Check under the vehicle for fresh oil puddles or drips. Inspect the valve covers, oil pan, front and rear main seals, and oil filter housing for any signs of leakage.
  • Inspect spark plugs: Remove and inspect spark plugs. Oily or carbon-fouled spark plugs are strong indicators of oil burning inside the combustion chambers.
  • Check PCV valve: A malfunctioning PCV (Positive Crankcase Ventilation) valve can contribute to oil consumption. Remove and inspect it for clogging or damage. A simple shake test can sometimes indicate if it's stuck.
  • Observe exhaust smoke: Have a friend watch the exhaust during cold starts, hard acceleration, and deceleration after coasting. Blue smoke confirms oil burning.
  • Compression and leak-down test: For more advanced diagnostics, a compression test and leak-down test can help identify worn piston rings or valve seals, which are common culprits in oil consumption issues. Refer to comprehensive repair guides for detailed instructions on these tests.

Common causes (most likely first)

For the 2017 Subaru Impreza, several factors can lead to excessive oil consumption:

  • Worn PCV (Positive Crankcase Ventilation) valve: A clogged or faulty PCV valve can create excessive crankcase pressure, forcing oil past seals and into the intake manifold to be burned.
  • Degraded valve stem seals: Over time, the rubber valve stem seals can harden or crack, allowing oil to seep past the valve stems and into the combustion chambers.
  • Worn piston rings (specifically oil control rings): This is a more significant internal engine issue. The oil control rings are designed to scrape oil from the cylinder walls. If they become stuck, worn, or carbon-fouled, they fail to do their job, leading to oil burning.
  • External oil leaks: While not technically

This guide is not a substitute for OEM service procedures; use a qualified technician for safety-critical repairs.

Frequently asked questions

How urgent is this problem?

If symptoms are worsening or safety systems are affected, diagnose soon; minor issues can often wait for a scheduled service visit.

Can I drive with this issue?

Short trips may be acceptable for some faults, but stop driving if you notice overheating, loss of braking, steering problems, or strong fuel smells.

Do I need a dealer scan tool?

A basic OBD-II scanner helps confirm codes; some steps still need visual checks and meter tests described above.

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