I’ve been getting oil on the driver side underneath the valve cover, and when I took it to Subaru for another item they stated that the valve cover was leaking, “that there is oil all over the engine”, and5offered to fix it for $4,000. Aghh!
I understand from my research that the 14mm fasteners on the valve covers are often weak and heat damaged and snap on removal. So the dealerships routinely pull the engine to do this work, expecting to have to drill out one or more. While the job can be done by getting some access and jacking up the engine itself, it looks like a nightmare as described by several mechanics on the web.
While I understand completely that oil seal additive is not the correct way to make the repair, being retired and having $20 but not $4,000, I bought two bottles of Blue Devil oil leak fix, enough to an treat 8 to 12 quart crank case (the 3.6 is 7 quarts).
On my last oil change, I selected Mobile One full synthetic high mileage 5w-30, which also claims to have treatment for leaking seals.
I also added 1.5 bottles of the Blue Devil oil seal product. As a chemist I understand these contain an ethyl glycol ether that expands the rubber in the seals. There are posts that say it won’t work at all on a Subaru because of the seal type and there are posts that say it works great, mostly from the manufacturer. Virtually nobody says it can hurt your engine if used per instructions.
I let the engine run for 2 hours, about an hour of which was at highway speeds after the oil change and leak treatment additive. I used engine degreaser, low in the engine, avoiding electrical components, on the valve covers to get rid of any residual oil. I did this on a cold engine and used only a garden hose to rinse, not a power washer.
Two days later I have absolutely no leaks on a piece of cardboard placed under the previously leaking area. The dark area on the cardboard in the photo is just a shadow. We’ll see how long this lasts.
