Vehicles using EJ15 engine list:

Engine EJ15

Symptoms:
- Rough idling or stalling
- Reduced power and acceleration
- Excessive oil consumption or leaks
- Engine overheating
- Unusual noises such as knocking or ticking

Diagnosis:
- Check for vacuum leaks and intake manifold gasket condition
- Inspect spark plugs and ignition coils for wear or fouling
- Perform a compression test to assess cylinder health
- Examine the timing belt for wear or damage
- Inspect coolant levels and radiator condition
- Look for oil leaks around valve cover gaskets and oil seals

Fixes:
- Replace worn or fouled spark plugs and ignition coils to restore proper combustion
- Repair or replace vacuum hoses and intake gaskets to eliminate air leaks
- Change the timing belt at recommended intervals (typically every 100,000 km) to prevent failure
- Fix oil leaks by replacing valve cover gaskets and seals as needed
- Flush and replace coolant to prevent overheating and maintain engine temperature
- Address any mechanical issues found during compression testing, such as worn piston rings or valves

Prevention:
- Follow the manufacturer’s maintenance schedule strictly, especially timing belt replacement
- Use high-quality engine oil and change it regularly to reduce wear and deposits
- Monitor coolant levels and condition to avoid overheating
- Avoid prolonged idling and aggressive driving to reduce engine stress
- Regularly inspect and replace air filters to ensure clean airflow
- Address minor issues promptly to prevent escalation into major engine problems