Corrective Action For High Oil Consumption

Conditions 

A new and improved type of piston ring was introduced for naturally aspirated engines from model year 1999 inclusive and for turbocharged engines from model year 2000 inclusive. From model year 2000 inclusive the same piston rings are used on both naturally aspirated engines and turbocharged engines.

A car with an engine with the new piston rings can be expected to use 0.05-0.15 liters of oil every 1000 km.

A car with an engine with the earlier piston rings can be expected to use 0.10-0.20 liters of oil every 1000 km.

If the engine consumes more than 0.4 liters of oil every 1000 km, the following checks must be carried out to check whether the oil consumption problem is in the cylinder head, crankcase ventilation or piston ring and sleeve surface.

Check 

Remove the intake manifold.

Check for oil film or drops of oil in the cylinder head intake passage and/or oil on the valve stem and top of the valve crown.

Conclusions 

If there is not an abnormally large amount of oil in the intake passage and valves and the oil consumption gradually, from being acceptable, begins to quickly increase, or consumption is between 0.30-0.80 liters per 1000 km, the problem is in the piston, piston ring or cylinder sleeve surface.

Faults in valve stem seals for example, or internal leakage in the cylinder head cannot be completely ruled out.

If the oil consumption has always been high, or there are traces of oil in the intake passage and valves, or the oil consumption is above 0.80 liters every 1000 km, the problem is probably in the cylinder head.

The cause could be leaking valve stem seals, internal leakage in the cylinder head or a fault in the crankcase ventilation (other than a blockage).

Corrective actions 

If the problem seems to be in the crankcase ventilation, this must be thoroughly checked and remedied if necessary, before reconditioning or replacing the cylinder head.

If the problem seems to be with the piston, piston ring or cylinder sleeve surface, the engine should be reconditioned or if necessary, replaced.