My 2006 s40 burns oil,
Is your oil clean,???? It may very well have good rings. Did the car ever "seriously" overheat, proir to this happening.??? If so, the valve seals, on some cars have boots, that look like umbrellas, that sit on the valve stem, between the valve stem & spring. A lot of foreign design engines, only use "o" rings. If the engine got hot enough, they can get brittle & break off. The oil that it is supposed to stop, runs down the valve, into the combustion chamber, & gets burned off. You will have a wet, blck reside inside the mouth of the exhaust pipe ir this is the problem. Then a valve job,or some GOOD nechanics, can add new seals, without removing the engine heads, the prefered, most inexpensive fix.