Vehicles using AZJ engine list:

Engine AZJ

Symptoms:
- Rough idling and hesitation during acceleration
- Engine misfires or loss of power
- Increased oil consumption and occasional smoke from the exhaust
- Check Engine Light (CEL) illumination
- Overheating or coolant leaks

Diagnosis:
- Inspect ignition coils and spark plugs for wear or failure, as these are common causes of misfires.
- Check for vacuum leaks around intake manifold and hoses which can cause rough idling.
- Perform a compression test to rule out internal engine wear or valve issues.
- Examine the PCV (Positive Crankcase Ventilation) system for clogging or malfunction, contributing to oil consumption.
- Inspect coolant hoses and thermostat for leaks or failure leading to overheating.
- Scan the ECU for stored fault codes to pinpoint sensor or system faults.

Fixes:
- Replace worn or faulty spark plugs and ignition coils to restore smooth engine operation.
- Repair or replace damaged vacuum hoses and intake gaskets to eliminate leaks.
- Service or replace the PCV valve to reduce oil consumption and prevent sludge buildup.
- Flush and replace coolant, repair leaks, and replace faulty thermostat to maintain proper engine temperature.
- Address any detected internal engine issues based on compression test results, such as valve seals or piston rings.
- Clear ECU fault codes after repairs and verify resolution of symptoms.

Prevention:
- Follow regular maintenance schedules including timely spark plug and ignition coil replacement.
- Use quality engine oil and change it at recommended intervals to prevent sludge and wear.
- Regularly inspect and maintain cooling system components to avoid overheating.
- Keep the PCV system clean and functional to reduce oil consumption and emissions.
- Address minor symptoms early to prevent escalation into major engine problems.