Vehicles using SKYACTIV-G 1.5 engine list:

Engine SKYACTIV-G 1.5

Symptoms:
- Rough idling or engine hesitation during acceleration
- Reduced fuel efficiency compared to expected performance
- Occasional engine knocking or pinging sounds
- Check Engine Light (CEL) illumination
- Minor oil consumption or oil leaks around the valve cover gasket

Diagnosis:
- Inspect ignition coils and spark plugs for wear or fouling, as misfires can cause rough running
- Use an OBD-II scanner to check for error codes related to fuel trim, misfires, or knock sensors
- Examine the intake manifold and PCV system for carbon buildup, which can affect air-fuel mixture
- Check for oil leaks around the valve cover gasket and camshaft seals, common wear points
- Monitor fuel system pressure and injector performance to rule out fuel delivery issues

Fixes:
- Replace worn or fouled spark plugs and ignition coils as needed to restore smooth combustion
- Clean the intake manifold and throttle body to remove carbon deposits, improving airflow
- Repair or replace leaking valve cover gaskets and seals to prevent oil loss and contamination
- Update engine software if Mazda has released technical service bulletins addressing engine management improvements
- Use high-quality fuel and oil to minimize carbon buildup and wear

Prevention:
- Follow Mazda’s recommended maintenance schedule, including timely spark plug replacement and oil changes with specified grade oil
- Use top-tier gasoline to reduce carbon deposits and maintain combustion quality
- Periodically inspect and clean the PCV valve and intake system to prevent buildup
- Avoid extended idling and aggressive driving to reduce engine stress and knocking risk
- Keep the cooling system in good condition to prevent overheating, which can exacerbate engine wear

By adhering to these guidelines, owners can maintain the reliability and efficiency of the SKYACTIV-G 1.5 engine across Mazda 2 and MX-5 models.