2001 LGT burning oil.

[beastman]

My wagon is burning oil. I've been told it's my piston rings. Just curious if this is an urgent fix, and how much I can expect to pay for the job if I don't do it myself. I do keep an eye on the oil every couple of days, and make sure it's at a decent level for the time being.

[ouch1011]

Burning or leaking?

Piston rings are a rare failure on these engines unless the engine was damaged in some other way (overheated, run low on oil, washed down, etc) or the engine is incredibly high mileage (like 250k miles or more)

Do you get any smoke from the exhaust? If so, when? Piston rings usually cause the most smoke under high loads---full throttle, climbing hills, etc... Valve seals (another cause of oil consumption) usually cause smoke on start-up or on initial acceleration after idling. You may not get any smoke out the exhaust despite burning oil because properly functioning catalytic convertors will pretty much elminate oil smoke unless it is really excessive.

You could also perform a compression test. If one of the compression rings is causing blow by and oil consumption, you will have low compression on 1 or more cyls. But you could still have an oil ring failure and not see any compression issues.

[beastman]

Very informative, thanks. I haven't noticed any smoke, but I'm always inside the car. I do smell oil if I'm heavy on the throttle, and sometimes right when I start the car.

[Miker104]

How many miles on the engine?

[green97gt]

have you crawled under and eyeballed the motor, every subaru ive seen with decent miles on it had front seal/valve cover leaks, unless theyve already been replaced.

with the way these motors are set up it leaks right onto the exhaust, causing a stink, and sometimes if bad enough some smoke.

a leaky PS pump can also cause hot smell from the exhaust.

[beastman]

It's got 147k miles.

I haven't noticed any leaks. I've parked overnight in a concrete garage and nothing hits the floor. I also ripped out the foamy stuff in the rain tray because I thought that might be absorbing leaks. Nothing noticeable since. There is some minor oil/gunk/buildup around the oil pan.

I feel like if it was leaking as much as I'm adding, I'd be seeing it under the car like I did with both my civic's main seal and my integra's distributer cap.

[Miker104]

Try changing the PCV valve if it has not been changed recently. A compression leak-down test can help determine if its rings or not. You could also try some of the oil "miracle cures" that the parts stores sell, cheaper than an engine rebuild.

Subaru engine rings seem to not generally be problems, but at 147k anything is possible. Engine rebuild if necessary will not be cheap unless you can do it yourself. Most places will want to install either a rebuilt engine or a used one. Try the easy stuff first.

[DCM-LEGACY]

seriously sounds like you have a bad oil pan gasket. it would cause oil to squirt out at high rpm onto the exhaust manifold where it would burn, then it leaks and at start up burns

[beastman]

So here's what things look like under the car. Oil pan gasket?

https://sl-i.net/FORUM/images/imported/2010/05/4630180159_bc2efff46a_b-1.jpg

[nomad666666]

Valve stem seals or blow-by.

[DCM-LEGACY]

yep looks like oil pan gasket

[ouch1011]

That is a very minor oil pan gasket seep. I doubt you would even notice that loss on the dipstick.

How much oil is it using? As in, how much oil are you having to add and how often? Some use is normal, up to about 1qt every 1000 miles. Any more than that is excessive.

Also keep in mind that high RPM operation will consume more oil. So if you are commuting like 50mi one way everyday on the highway at 80mph, then you are going to use quite a bit of oil.

[beastman]

I'm putting in a quart every time I fill up on gas, so between 300-400 miles.

[ouch1011]

I'd say that is excessive....lol

Well you could pull the spark plugs and have a look. Any cylinders that are burning oil will have deposits on the plugs. Pretty easy to do on the SOHC models.