Nissan Serena: MR20DD Piston Ring Oil Consumption on Direct Injection

The MR20DD 2.0-litre direct-injection engine used in the C27 Serena exhibits documented piston ring seating failures that allow engine oil to enter the combustion chamber and burn off. Affected vehicles consume 0.5 to 1.5 litres of oil per 1000 km under normal driving. The root cause is insufficient ring tension combined with the elevated crankcase pressure inherent to direct-injection combustion cycles. Nissan Japan issued an extended warranty campaign in the domestic market covering piston assembly replacement, but grey imports are not covered under that programme. If left unaddressed, catalytic converter contamination follows, raising repair costs substantially.

• Oil level dropping significantly between services without visible external leaks
• Blue or grey smoke from exhaust especially on deceleration or after idling
• Spark plug fouling on one or more cylinders
• Catalytic converter deterioration and associated P0420 code

1. 1

   Check the oil level and note its colour and smell; a burnt odour points to combustion oil loss.

2. 2

   Pull spark plugs and inspect for oil fouling.

3. 3

   Ask the seller to confirm how much oil was added between last two services.

4. 4

   If a workshop inspection is possible: A compression and leak-down test across all four cylinders will identify ring seal failure before purchase.

Parts involved: Catalytic converter.

$2,800 to $6,500 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 much oil have you added between oil changes?”
• “Has the engine ever smoked on startup or under engine braking?”
• “Has any warranty claim or recall been carried out on the engine?”
• “When were the spark plugs last replaced and what did they look like?”

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.