Vehicles using EJ204D engine list:

Engine EJ204D

Symptoms:
- Excessive oil consumption
- Coolant leaks or overheating
- Rough idling or misfires
- Loss of power or poor acceleration
- Check Engine Light (CEL) illumination

Diagnosis:
- Inspect for head gasket leaks, common in EJ204D engines, by checking for coolant contamination in oil or white smoke from the exhaust.
- Perform a compression test to detect cylinder sealing issues.
- Check for oil leaks around valve cover gaskets and oil seals.
- Scan the ECU for error codes related to misfires or sensor failures.
- Inspect the cooling system for leaks or malfunctioning components causing overheating.

Fixes:
- Replace the head gasket if leaks or compression loss are confirmed.
- Repair or replace faulty valve cover gaskets and oil seals to stop oil leaks.
- Clean or replace spark plugs and ignition coils to resolve misfires.
- Flush and replace coolant to maintain proper engine temperature.
- Address any sensor or ECU issues by replacing faulty parts or updating software.
- Regularly change engine oil and filters to prevent sludge buildup and maintain lubrication.

Prevention:
- Use high-quality engine oil and change it at recommended intervals to reduce wear and prevent sludge.
- Monitor coolant levels and condition regularly to avoid overheating.
- Avoid aggressive driving that stresses the engine and cooling system.
- Perform routine maintenance including spark plug replacement and ignition system checks.
- Address minor leaks or issues promptly to prevent escalation into major repairs.