P0011, a check engine story

[Power6]

Wife came home the other day, "Check engine light came on, car felt low on power merging on to the highway" on our 05 Outback XT with 96k miles.

I took it down to Autozone to pull the code, P0011 pass side AVCS. I know the Subarus but had not yet been acquainted with the dreaded P0011. The ride home I heard some odd noises, a sucking through a straw is the best I can say, confirmed that others heard this too googling around. I also heard some rattling.

Totally freaked out, I removed the banjo bolt screen on the pass side head. It was opaque, not even sunlight would shine through it. Code persisted, at least wasn't starving the turbo for oil any more.

Luckily we have a Subaru specialist shop less than a mile away, we dropped it off to have them sort it out. I figured the turbo was gone. They think the turbo is fine, a loose heatshield was rattling on the exhaust causing some noise. They are going to follow the Subaru TSB and do an oil flush to hopefully free up the AVCS and get us back to good.

This is what happens when you buy a turbo Subaru with an unknown history. We may have dodged a bullet here, for now. The shop says we should be running synthetic and change it every 3750.

Turbo owners make sure you change that oil frequently and check that banjo screen...

[1 Lucky Texan]

I think there are 2 more screens leading to the AVCS so, they are likely clogged too.

have you owned and maintained the car since new? How's the maintenance been and what oil and change interval do you use?

[Power6]

From my research, there are two screens, one is on the feed to the AVCS solenoid on the driver's side. The pass side feeds the turbo and the AVCS, and so is more critical. The AVCS system can survive a restriction of oil but the turbo needs good oil pressure to keep the bearings healthy.

The driver's side is also much more difficult to check, I believe at least the timing cover needs to be removed to access it, so I likely wouldn't address that one until I get the P0021 (driver's side AVCS) code. It may well be that the Subaru flush procedure will clean that screen out a bit as it is, so this may never be a problem.

We bought the car recently, used, I don't know the history of oil changes, so that is the issue. According to our Subaru shop oil needs to be synthetic and changed often to prevent this issue.

[1 Lucky Texan]

synthetics keep 'varnish' dissolved/suspended well. One reason synth looks so dark coming out. I'd expect it may also be able to 'clean' varnish from inside an engine previously using conventional oil - not sure, but, if so, switching might clean/flush out some of the screen clogging debris - i guess it depends on a lot of variables.

good luck

[Power6]

Thanks! I am wishing we just bought the H6 or non-turbo 4 probably would be less trouble, but we are making the best of it, want to get at least 50k more miles out of this car.

[1 Lucky Texan]

is there a procedure or video on how to clean these screens?

I dunno if my 06 has the screen but, I know it's never been examined.

I use synth that is changed much sooner than it 'should be' (on a normal car)

[bripp]

Thanks for the info; great info! My car threw a P0011 code recently and it has me super scared. I changed the oil and have made a few short trips here and there and the CEL hasn't came back on. I too bought a used 2.5XT w/no service records. I'm having a mechanic take a look at the banjo bolts this week. Do you recommend driving, or should I wait to have the screens replaced/cleaned/removed? How do you feel about moving the screens all-together? Since the code reads "Intake camshaft over-advanced" do you recommend having the belt looked at to see if it skipped some teeth? NIGHTMARE!!! I hope everything shakes down fine once it's diagnosed...

[OregonBP9]

Your belt didn't skip a tooth. Nearly impossible to happen. They break first. You either have a lazy OCV (they do tend to fail early and are uber easy to replace) or you have an oil starvation problem on the PS. Regarding the latter, you're ripe for a turbo (and ultimately engine) failure if you don't address the problem right away. Get that banjo filter out, change the oil, and if the code persists change out the OCV. The P0011 is highly correlated to turbo failure. It's very similar to a heart attack in humans... Fix it right away and you'll live a long life. Procrastinate and you're dead. It's an easy fix on your car, just don't blow it by wishing it better.

[Power6]

To echo above the P0011 has nothing to do with the timing belt, it is feedback from the variable cam advance system.

I would def recommend not driving the car if you can avoid it when you get this code. Yes taking the screen out is fine that is what I have done. There is a small risk if something bad happens to the motor you could ruin the turbo too, since the screen is not there to protect it from debris in the oil any more, but IMO the risk is worth it due to the known issue of the screen clogging.

We did not drive our XT very far with the code, the turbo still has a slightly "off" sound. I am going to have the endplay checked out, it may have been too late to save it, even though our mechanic thinks it is fine. The "oil flush" fix also caused/uncovered and oil leak on to the exhaust so that needs to be addressed anyways.

[OregonBP9]

I did away with the OEM oil feed altogether and went with one of these. Retains filtration to the turbo while eliminating risk of banjo bolt filter clog.

IP&T Filtered Turbo Oil Supply Line Kit