I have a 2012 A4 S line with 74000 mi and have oil consumption problems. I had the breather valve replaced and I just pulled the spark plugs off and noticed 3 and 4 have oil on them and looking down the hole i can see the two pistons are charred with oil on them... would you guys lean towards a piston ring issue? And do you think audi would cover it? I am burning a quart about every 300 mi! Please help!