massive oil leak - none on ground

Hi. My wife has a 2005 NON-turbo Legacy. She came home the other night complaining it lacked power when she pulled out to pass.

I immediately checked the oil (among other things) and found that (much to my embarrassment) the oil was just barely touching the stick -- but it was nearing the time for an oil change, so I didn't think a lot about it. Especially because I could see no extra oil on the car anywhere (including the engine), nor on the ground. Still, I thought it curious because at 133,000 miles it's has always gone all the way between oil changes without using hardly a drop. I thought "maybe a dirty PCV valve?".

So I put some oil in, and told her not to worry about it just now. HOWEVER, it looks like things are not so simple. I didn't have enough to fill the dipstick to full up, but did have enough to get it to about half way between the low and full dots on the dipstick. She came home Friday after driving the car about 60 total miles and the oil was just below touching the dipstick at all. I.e., she lost all that oil in one commute.

There is no smoke from the exhaust -- which is why I initially thought of a PCV value. But that seems like a LOT of oil for just a PCV valve problem? Anyone here with a lot of engine repair knowledge on Subies who could suggest what this could be? I'm starting to worry that it may have a cracked piston ring or other serious internal trauma.

Any insight, greatly appreciated.

Thanks.

Hello,

So oil in our engines can be illusive, like a multi-colored unicorm if you will. Some people burn, and have burned, 1.5 qrts every 3.5k miles (or regular OCI) for thousands of miles without issue. Others neglect oil and change it when they remember and have not problems ever other follow all the rules then let it run low once and POP!

I would conduct an oil change to get to a known oil level then start to monitor it over the next few weeks (500-1000 miles). Old oil breaks down and is used up in the engine, to be simplistic, you wont see blue smoke or gunk near the rear of the block or leak prone areas.

To test if the PCV is gummed up take the intake box off (the one attached to the Throttle body) and look inside if there is moist oil accumulated in there then clean or replace the PCV. If it is dry or there is dried oil in there that is normal for that mileage, but still clean the PCV to be safe.

If there is no smoking, visible leaks or oil in coolant you have a normally operating EJ253 with high miles on the clock. It may start to use oil more so than when it had 90K miles. I have 135K on my 08 2.5i I use .5 qrt every 3.5K miles, in lieu of "making the oil last" I just change it and have a known observation point 4-5 times per year.

You mention 2 things that stand out.

1. Wife mention loss of power when passing

2. Loss of oil during a 60 mile commute.

Based on these 2 things it's telling me you may have lost a cylinder/piston or a possible burnt valve. That is a lot of oil to pass through a small PCV valve in such a small time period. It will not hurt to replace the PCV and see if it improves any. If you continue to lose this much oil, you're going to be looking at a compression test to determine the health of your cylinders/pistons.

Other things to check:

- Check your coolant for oil. If there's oil in the coolant then you have a blown head gasket.

- Inspect head gasket for leaks

- Inspect valve cover for leaks