I have a 2007 Subaru Forester with a N/A 4 cyl and 5 speed manual tranny with just over 200,000 miles on it. For the past few months, it’s been using between 1 and 3 quarts of oil between oil changes. My mechanic and I can’t find any signs of a leak that big ( there’s a cam seal with a light sheen of dusty oil around it, and some dusty oil on the driver’s side head, just below the oil filler neck.
I put a UV dye in the oil, and the only spot that glowed under a black light was the bottom of the cam sensor, which doesn’t connect to any oil passages.
I noticed it uses more oil if I keep the RPMs high ( after a week of driving through the hills of Kentucky ).
I changed the PCV valve, which was very oily ( I shook it to see if it rattled and oil rained out of it ). But I lost a quart of oil in the week since I replaced that.
Does anyone have any ideas of what it could be, or where to look?