Daihatsu Tanto: KF-VE Engine Oil Consumption from Worn Piston Rings

The KF-VE 660cc naturally aspirated engine suffers from accelerated piston ring wear and carbon build-up on the ring grooves, causing the oil control rings to stick and lose sealing effectiveness. Oil passes into the combustion chamber past worn or stuck rings and is burned, causing measured consumption rates of 0.5–1.5 litres per 1000 km. This is a design characteristic of the small-bore, high-revving KF engine when used predominantly on short urban trips where the engine does not reach full operating temperature.

• Oil level drops visibly on the dipstick between standard service intervals without any external oil leaks
• Blue smoke emitted from the exhaust on deceleration or on cold startup that clears within one to two minutes of driving
• Spark plugs show oil fouling with wet, dark deposits on one or more electrodes when inspected
• Occasional misfire on cold start that clears once the engine warms, caused by oil-fouled spark plugs

1. 1

   Check oil level on the dipstick and compare against recorded level at last service.

2. 2

   Conduct a timed oil consumption test over 3000 km under normal driving conditions — consumption above 0.5 L per 1000 km is abnormal.

3. 3

   Inspect all three spark plugs for oil fouling (wet or black oily deposits on the electrode).

4. 4

   Check the PCV valve for blockage as a clogged PCV accelerates ring carbonisation.

5. 5

   If a workshop inspection is possible: Perform a dry and wet compression test on all three cylinders — a wet test improvement of more than 20 psi indicates ring wear.

$1,800 to $4,500 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 often is the oil level checked between services, and has it ever been low?”
• “Is there any blue smoke from the exhaust when starting the car or lifting off the throttle?”
• “What oil change interval has been followed and what type of oil is used?”

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.