Vehicles using FB20 engine list:

Engine FB20

Symptoms:
- Excessive oil consumption
- Rough idling or misfires
- Check Engine Light illumination
- Reduced engine performance
- Unusual engine noises, such as ticking or knocking

Diagnosis:
- Inspect for oil leaks around valve cover gaskets and oil seals
- Perform compression and leak-down tests to assess cylinder health
- Scan for diagnostic trouble codes (DTCs) related to ignition coils, fuel injectors, or camshaft timing
- Examine spark plugs for fouling or wear
- Check timing chain tension and condition

Fixes:
- Replace faulty valve cover gaskets and seals to stop oil leaks
- Change spark plugs and ignition coils if misfires are detected
- Clean or replace fuel injectors to restore proper fuel delivery
- Repair or replace timing chain components if wear or slack is found
- Address carbon buildup by using fuel system cleaners or professional intake cleaning
- Regular oil and filter changes with manufacturer-recommended grades to prevent sludge and wear

Prevention:
- Adhere strictly to scheduled maintenance intervals, especially oil changes using high-quality synthetic oil
- Use recommended fuel grades to avoid carbon deposits
- Monitor engine performance and address minor issues promptly to prevent escalation
- Avoid extended idling and aggressive driving to reduce engine stress
- Periodically inspect and replace air filters to ensure proper air intake and combustion

By following these diagnostic steps and maintenance practices, owners of Subaru vehicles equipped with the FB20 engine can minimize common issues and maintain reliable engine performance.