Subaru Outback Forums banner

1 - 13 of 13 Posts

·
Registered
2012, Outback, 3.6R
Joined
·
129 Posts
Discussion Starter #1
I started a couple of threads in the Gen4 forum discussing my 2012 3.6 oil level issue (low oil light came on at 4k miles between oil change interval of 7500 miles). It was fixed by adding a quart of oil. The bottom line is that Subaru says it is OK if you burn a quart of oil every 1500 miles but most other people believe that is absurd.

One question that wasn't answered but probably applies to any car in general is this:

When a car "burns" oil between intervals, where does it go? I have no obvious oil leaks but other threads have stated that it can very slowly bleed out of seams throughout the engine. Wouldn't that end up with the outside of my engine slowly getting caked in oil?

The fact that people call it "burned oil" makes me think it is actually being burned (changing state) and must still be in the oil system. Wouldn't that result in a LOT of contaminents in the oil system and ruin it eventually?
 

·
Registered
2003 Outback Limited 2.5L H4 5MT Regatta Red Pearl w/ lift and audio system
Joined
·
1,256 Posts
It means that the oil is getting past the piston rings and into the combustion chamber, and there it gets burned. In an ideal world, all of the oil would stay on the crankcase side of the piston and all of the fuel and fire would stay in the combustion chamber. While some cars come very very close to zero oil consumption (My stepdad's old 4runner had 15k MILE oil change intervals and burned no appreciable amount of oil in that time), SOME oil is burned. Some cars burn a lot of oil. A quart every 1500 miles is absurd. My '03 Outback burns a quart every 3000, and even that is not a good sign.
 

·
Registered
2007 Outback XT Ltd
Joined
·
847 Posts
Leaking seals or gaskets, worn or broken oil control rings, scored cylinder walls, worn valve guide seals - they can all lead to oil in the cylinders. The pistons are VERY efficient at moving air, and when there is an opening into the lubrication system that isn't supposed to be there, they will suck oil in like you wouldn't believe.

It can be as simple as a stuck PCV valve that is letting oil into the intake, and from there into the chambers. That is the first thing I would check. If oil pours out of the pcv valve hose when you take it off, there is a problem. The valve contains a ball that acts as a one way check valve, if it doesn't rattle freely when you shake it, it is no good. They are dirt cheap, so you might as well just change it while you are there.

If you have eliminated external sources, then you need to go inside. To see where it is going, pull the plugs and see if any are caked with carbon. If so, there is your culprit.

Then you need to determine if the problem is in the heads or in the block. A pro can do some testing for you like a peek inside the cylinders with a boroscope and a leak down compression test. He will give you the bad news (head rebuild) or the REALLY bad news (new engine required).

Good luck. Hopefully it's just a PCV valve..... I would push Subaru hard on this issue.

BTW it is REALLY bad to not check the oil routinely. 4000 miles is way too long, as you discovered. 1000 would be fine. I check mine more often than that.

John Davies
Spokane WA USA
 

·
Registered
2020 Touring XT, 2013 Outback Lim SAP 270K, 2003 Outback Lim MT 2.5L, 241K..
Joined
·
2,182 Posts
I started a couple of threads in the Gen4 forum discussing my 2012 3.6 oil level issue (low oil light came on at 4k miles between oil change interval of 7500 miles). It was fixed by adding a quart of oil. The bottom line is that Subaru says it is OK if you burn a quart of oil every 1500 miles but most other people believe that is absurd.

One question that wasn't answered but probably applies to any car in general is this:

When a car "burns" oil between intervals, where does it go? I have no obvious oil leaks but other threads have stated that it can very slowly bleed out of seams throughout the engine. Wouldn't that end up with the outside of my engine slowly getting caked in oil?

The fact that people call it "burned oil" makes me think it is actually being burned (changing state) and must still be in the oil system. Wouldn't that result in a LOT of contaminents in the oil system and ruin it eventually?

I learned from my 03 OB - that my previous experiences of oil consumption (toyotas) did not apply. The 03 OB went through a lot of oil - even fairly early on in its life.
I spoke about this at length with my Subaru mechanic who USED to work for Subaru for a while - and has run an independent Subaru shop for years and comes highly recommended. He said it was very common for Subarus to go through oil more than some other cars - but he also attributed it to conventional oil use.
He said it was pretty normal.
My 03 OB in the end went through oil like crazy - never a leak though.
 

·
Registered
2020 Touring XT, 2013 Outback Lim SAP 270K, 2003 Outback Lim MT 2.5L, 241K..
Joined
·
2,182 Posts
My dealer uses castrol gtx. Would a different oil burn less?
I honestly dont know. But he insisted synthetic would burn less in general for my 03. I never tried it.
 

·
Registered
2012 limited, white, no moonroof or nav
Joined
·
1,698 Posts
First thing to try when an engine uses excessive amounts of oil is to change the PCV valve.......A sticky or defective valve can suck up a fair amount of oil.

The second thing to try is too drive it hard. Going up a long mountain as fast as you dare a few times may help. Anything that puts the cylinders under enough heat and pressure to seat the rings may be effective. The more miles on the motor before doing this, the less likely it is to be effective. I like to give new motors some full throttle runs just past 1k miles. If you already have 15k, it will take a lot more hammering. It will not likely work at all by 30k. Good luck.
 

·
Registered
Joined
·
232 Posts
I started a couple of threads in the Gen4 forum discussing my 2012 3.6 oil level issue (low oil light came on at 4k miles between oil change interval of 7500 miles). It was fixed by adding a quart of oil. The bottom line is that Subaru says it is OK if you burn a quart of oil every 1500 miles but most other people believe that is absurd.

QUOTE]
Hi,

While the question has been answered, the oil consumption is certainly excessive. One thing that can affect how an engine consumes oil over its lifetime is the technique used to "seat" the piston rings during the break-in period.

How did you break-in the engine?

Regards.
 

·
Registered
2012 Outback Limited 3.6R
Joined
·
7 Posts
I have same issue with my 2012 3.6R. The dealer keep saying its normal :(. as a matter of fact, I brought up same issue today during my 30K maintenance and dealer said that its normal ..again :(. oil level sensor is very sensitive according to them..whatever. Dealer said that just top it off whenever the oil level lights comes on
 

·
Registered
Joined
·
304 Posts
Oil use is a common and exceptable thing in Subaru engines.. Due to the cylinder bore having (no sleeves) especially in 2.5 engines, so reason subaru wants you and should check your oil in between changes of 3000mi and every 1000 miles.
And to add a mechanic mentioned to also stick with every 3000 mi oil change due to it being a boxster engine.
 

·
I simply cannot abide useless people.
2006 2.5i and 2002 3.0 wagons.
Joined
·
12,306 Posts
Exactly where does Subaru say 3000 mile OCI?

Please provide proof of your claim, which goes against all published literature I've seen.

And "3k because it is a boxer engine" is hogwash.
 

·
Registered
13 Outback 2.5 Premium CVT
Joined
·
340 Posts
My dealer made a special point to tell me how the Subaru plant produces practically zero garbage and are really environment friendly.

If your car is burning oil and the dealer is playing the "perfectly normal" game then try this for your next oil change at the dealer.

Tape a big sign to the back hatch that says

This Brand New Subaru burns oil and I apologize for polluting the environment but Subaru claims it is perfectly normal for new Subaru's to burn up too 5 quarts per oil change.


PS
Make sure you still have the dealers license plate holder advertising for him, they appreciate all the free advertising you do for them.
 

·
Registered
2005 OBW 2.5L, 1989 Subaru Justy, RIP Blu
Joined
·
7,355 Posts
I started a couple of threads in the Gen4 forum discussing my 2012 3.6 oil level issue (low oil light came on at 4k miles between oil change interval of 7500 miles). It was fixed by adding a quart of oil. The bottom line is that Subaru says it is OK if you burn a quart of oil every 1500 miles but most other people believe that is absurd.

One question that wasn't answered but probably applies to any car in general is this:

When a car "burns" oil between intervals, where does it go? I have no obvious oil leaks but other threads have stated that it can very slowly bleed out of seams throughout the engine. Wouldn't that end up with the outside of my engine slowly getting caked in oil?

The fact that people call it "burned oil" makes me think it is actually being burned (changing state) and must still be in the oil system. Wouldn't that result in a LOT of contaminents in the oil system and ruin it eventually?

Oil isnt burnining in the traditional sense, which is something people do not understand. One of the jobs of engine oil is to COOL the pistons. the oil is squirted under the piston face and skirt. Since modern engines run extreemly clean, they are running at high combustion temps. With lighter pistons (emissions, freer reving) It is hard to get rid of that heat through the usual means. Engine oil is squirted to cool things down, and in the process some of it evaporates. Then it goes into the combustion chamber via the PCV system. Some engines will have minutes amount of oil go down the valve stems, some more then others, and burn oil that way.

Oil level need to be checked every 1000 miles. Using 1 qt between oil changes in any engine is normal. 1 qt per 1000 miles while still acceptable is considered unusal and needs to be investigated.

thats where it goes.
 
1 - 13 of 13 Posts
Top