Vehicles using B204L engine list:

Engine B204L

Symptoms:
- Loss of power or reduced turbo boost performance
- Rough idling or engine misfires
- Oil leaks around the valve cover or turbocharger area
- Overheating or coolant loss
- Check engine light illumination with related fault codes

Diagnosis:
- Inspect turbocharger for shaft play, oil leaks, and proper boost pressure
- Check for vacuum leaks in hoses and intercooler piping
- Perform compression test to assess cylinder health
- Examine ignition components (spark plugs, coils) for wear or fouling
- Inspect valve cover gasket and turbo oil lines for leaks
- Scan engine control unit (ECU) for stored fault codes related to sensors or emissions

Fixes:
- Replace worn or damaged turbocharger components or the entire turbo if necessary
- Repair or replace cracked or leaking vacuum hoses and intercooler pipes
- Change spark plugs and ignition coils as needed to restore smooth running
- Replace valve cover gasket and turbo oil feed/return lines to stop oil leaks
- Flush and refill coolant system to address overheating issues
- Clear ECU fault codes after repairs and perform test drive to confirm resolution

Prevention:
- Regularly change engine oil and use high-quality synthetic oil to protect turbo bearings
- Maintain cooling system with periodic coolant flushes and thermostat checks
- Inspect and replace vacuum hoses and intercooler pipes proactively to prevent leaks
- Use recommended spark plugs and replace them at specified intervals
- Avoid prolonged idling and aggressive driving to reduce turbo stress
- Monitor engine performance and address minor issues promptly before they escalate