Subaru XV: FB20 Excessive Engine Oil Consumption from Piston Ring Wear

The FB20 2.0-litre horizontally-opposed engine fitted to the GP-generation XV is known to consume engine oil at an abnormally high rate due to premature wear of the piston rings, particularly the oil control rings. The ring land geometry and oil control ring tension on early FB-series engines allowed oil to be drawn past the rings into the combustion chamber, burning it without producing obvious blue smoke until consumption became severe. Left unaddressed, this leads to low oil level damage to bearings and camshaft journals, and can cause catalytic converter contamination from unburnt oil residue.

• Oil level drops by 1 litre or more per 1,000 km without any visible external leaks
• Spark plugs show heavy carbon fouling or oily deposits, particularly on the front cylinder pair
• Blue-grey smoke from the exhaust briefly on cold start-up or during overrun deceleration
• Oil consumption warning light or low-oil notification triggered between normal service intervals

1. 1

   Check oil level at every fuel stop and measure consumption over a known distance.

2. 2

   Pull the dipstick and inspect for unusually low level after 1,000–2,000 km intervals.

3. 3

   Remove spark plugs and inspect for oily or carbon-fouled tips, particularly on cylinders 1 and 2.

4. 4

   Request any workshop history showing repeated top-ups.

5. 5

   If a workshop inspection is possible: A cold-start compression and leak-down test on each cylinder will confirm ring seal.

Parts involved: Catalytic converter.

$3,500 to $7,500 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.

• “Can you show me the service history and confirm how often oil top-ups have been needed between services?”
• “Has the engine ever required a piston ring replacement, short-block rebuild, or been subject to any Subaru warranty or goodwill repair for oil consumption?”
• “When were the spark plugs last replaced, and can I see the old plugs?”

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.