I would try engine/motor flush and see if the oil consumption decreases.
*) Always change oil filter after engine flush.
*) Don't drive the car but give the treatment while the engine is idling.
*) Read instructions carefully on the product.
There are several brands on the market. Forte (FORTE ADVANCED FORMULA ENGINE MOTOR FLUSH)
is the best and the most expensive. In some countries it's regarded as a professional garage use only
but you can buy it from ebay (also much cheaper price).
There are other brands which are cheaper like Liqui Moly, STP, CRC, Valvoline and etc.
I hope this helps.
PS: Oil consumption in mine is around ~0.25l (max 0.5l) for 10k km.
===
Edit: The real solution is to replace the seals I guess, for that engine top cover will be removed and it is not a "big" job like head gasket change.


