Vehicles using B6304T3 engine list:

Engine B6304T3

Symptoms:
- Rough idling and hesitation during acceleration
- Loss of power or reduced engine performance
- Engine misfires or stalling
- Increased oil consumption or visible oil leaks
- Check Engine Light (CEL) illumination with related fault codes

Diagnosis:
- Inspect ignition coils and spark plugs for wear or damage, as misfires are common
- Check for vacuum leaks around intake manifold and hoses causing rough idling
- Perform a compression test to assess cylinder health and detect possible head gasket issues
- Scan for diagnostic trouble codes (DTCs) related to fuel injection, ignition, or emissions systems
- Examine turbocharger operation and boost pressure for signs of failure or leaks
- Inspect PCV (Positive Crankcase Ventilation) system for clogging or malfunction leading to oil consumption

Fixes:
- Replace worn or faulty spark plugs and ignition coils to restore smooth combustion
- Repair or replace damaged vacuum hoses and intake gaskets to eliminate leaks
- Address any head gasket leaks or cylinder sealing issues found during compression testing
- Clean or replace clogged PCV valves to reduce oil consumption and maintain crankcase pressure
- Service or replace the turbocharger if boost pressure is insufficient or if mechanical failure is detected
- Regularly change engine oil and use manufacturer-recommended grades to protect engine internals

Prevention:
- Follow Volvo’s recommended maintenance schedule strictly, including timely spark plug and oil changes
- Use high-quality fuel and engine oil to reduce deposit formation and wear
- Avoid prolonged idling and aggressive driving to minimize stress on turbocharger and engine components
- Periodically inspect vacuum lines and PCV system for early signs of wear or blockage
- Ensure cooling system is functioning properly to prevent overheating and gasket failures

By adhering to these diagnostic steps, fixes, and preventive measures, owners of the Volvo S60 T6 AWD R-Design (2014–2015) with the B6304T3 engine can maintain reliable performance and reduce the risk of common engine issues.