Volvo XC60: B6304T T6 engine excessive oil consumption and piston ring wear

The B6304T/T2/T3/T4 inline-six 3.0-litre twin-scroll turbocharged engine (T6 variants) is prone to accelerated piston ring wear, particularly the oil control rings. Carbon deposits cause the oil control rings to stick in their grooves, losing the ability to scrape oil off the cylinder walls. This results in oil being burned in the combustion chamber. Consumption rates of one litre per 2,000–3,000 km are common on higher-mileage examples. Over time, catalytic converter contamination from oil burn leads to secondary failures including blocked cats and oxygen sensor faults.

• Oil consumption requiring top-up between services
• Blue smoke from exhaust on acceleration or after overrun
• Fouled spark plugs with oily deposits
• Catalytic converter fault codes after prolonged consumption
• Burning oil smell from engine bay

1. 1

   Check the oil level and note whether it is below the dipstick maximum despite being recently serviced.

2. 2

   Inspect the spark plugs if accessible — oil fouling on the electrode indicates ring wear.

3. 3

   Look for blue haze from the exhaust during a hard acceleration test.

4. 4

   Ask the seller how often oil is topped up between services.

Parts involved: Catalytic converter.

$3,500 to $9,000 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

• “How often does the oil level need topping up between scheduled services?”
• “Has the engine ever been investigated for oil consumption?”
• “Have the spark plugs been replaced recently and what condition were they in?”

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.