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Discussion Starter #1
Yup, read that right. The car left the whole family stranded on the side of a busy highway for 2 hours, could get it started after cranking 15 - 20 seconds with foot on the floor, and it would rev upper band (over 3000 RPM) fine, but would die below that, or when put in gear. The only codes it threw were misfire on all 6 cylinders (yes, P0301, P0302, P0303, P0304, P0305, and P0306). Dropped it at Subaru and they took a look at it and $250 later, were still unable to tell me the cause of the issue. Brought it home and it is currently in the driveway and trying to decide what to do with it.

The tech notes were simple...oil leaks on valve covers, gunked up PCV, pulled spark plug and gas smelled stale (huh, had just filled up 3 days prior from under 1/4 tank). I asked for a fuel pressure test, as that is how it was acting, but the tech claimed it came back at >50psi, so that should be good.

I am at my wits end with this thing. We got screwed HARD when we bought it and are so upside down on it I hate to sell it, but it's not giving me any choice.
 

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Sorry to hear that....definitely...if you don't feel safe and can't get to that point, get something you can trust.
 

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Tech notes are garbage. Not helpful at all. None of that has anything to do with your issue.

No other codes. Just misfire? It makes you want to start to think about timing chain issue. Do you hear any chain rattle?

What year? How many miles?

Tom
 

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Discussion Starter #4
No other codes, just the misfire. It is running very rough, but it is running. I replaced the PCV and it did seem to help slightly, but very little. I figured a $16 part was worth trying, even though that made damn near zero sense. I did hose down the intake and every vacuum line with starting fluid to see if there is a vacuum leak anywhere and found nothing.

It's a 2008 and unknown miles. Originally from Canada, and when it was imported had to change the dash. Clock has 129k on it. Have a couple things I am going to try, but damn near ready to just scrap this thing even after new rims, tires, front struts, front brakes, and fuel injector wiring harness.
 

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Oh boy... New dash... That has a lot of complications to it unless done right. The ECU directly fires the spark, so it could be the ECU, but it's rare that all 6 would go at the same time. Which is why timing chain comes to mind first since that affects all at the same time.
 

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Discussion Starter #6
Just had it running, and it was running VERY rough, let it idle for a while, tapped on camp position sensors, cleaned the MAF sensor (before running it of course), and tapped on the throttle body/throttle assembly. Tapping on the throttle body cleaned it up slightly, but not much. Let it run while I came inside to look for my automotive stethoscope so I could listen to the heads and timing chain. Went out and heard a slight tick which sounded like valve noise on cylinders 1 and 3, normal on 2, 4, 5, and 6, with nothing odd on the timing chain area. Decided to rev the engine with the door open and listen to what it was doing. Reved great just like normal, then when came down to idle, it was purring like a kitten.

Seeming like maybe the AVCS is sticking, or an electrical gremlin is causing the issues.
 

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I have an 06 with the 3 liter but had similar problems. Check the AVCS, when they go it causes crazyness and limp mode. Mine ended up being clogged banjo bolts on both oil lines on the sides of the heads. Common with the turbo crowd but was a pita to research on these becas. Seems like they were cutting oil pressure to just the avcs modules. Not sure if the 3.6 on yours still has filters but worth a google as it was an easy fix. Lots of folks say an oil change helps so if that's the case your root cause is likely still the micro filters.
 

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Simoltz, did you have codes? Usually AVCS due to low oil pressure comes with a code from a sensor. Similarly for most electrical issues. All he has is misfires on all cylinders. My best guess is fuel issue. I believe the seal on the gas tank is a known failure point on 3.0L subarus and could cause this symptom. Check subaruoutback.org for this.
 

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Discussion Starter #9
It seems like the AVCS, as when I bounced off rev limiters (after letting it warm up for a while) it started idling fine. Or electrical and the vibration "fixed" it. My buddy who is a master Subaru tech thinks a stretched timing chain biased off the information I have and said if I had a scanner could check the cam/crank correlation...but the little ODBII scanners don't seem to have that information.
 

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Check out FreeSSM. I believe it does have that information. Good thread over on subaruoutback.org on getting that to work.

Tom
 

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Simoltz, did you have codes? Usually AVCS due to low oil pressure comes with a code from a sensor. Similarly for most electrical issues. All he has is misfires on all cylinders. My best guess is fuel issue. I believe the seal on the gas tank is a known failure point on 3.0L subarus and could cause this symptom. Check subaruoutback.org for this.
I did but I cleared my screenshot. It was both AVCS bank codes with 2 misfires. It was utterly weird which is why i called it out. I first cleaned one side's screen and all 4 codes came back in 30 miles. So I was ready to change the AVCS solenoids but figured it's inspect the passenger side screen and it was shot. Non visible but could hardly blow through it. I removed both and it's been 500 miles now with no codes. All I can think is one side being bad was causing the other side to not be able to compensate either. I've done a bunch of 2.5 work but this is my first 3 liter but I can't say anything has been this disconnected from causation for all the codes I got. Sorry I don't have more but for 30 min of your time check out the Banjo bolts just to see. May get lucky. Best of luck!
 

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I did but I cleared my screenshot. It was both AVCS bank codes with 2 misfires. It was utterly weird which is why i called it out. I first cleaned one side's screen and all 4 codes came back in 30 miles. So I was ready to change the AVCS solenoids but figured it's inspect the passenger side screen and it was shot. Non visible but could hardly blow through it. I removed both and it's been 500 miles now with no codes. All I can think is one side being bad was causing the other side to not be able to compensate either. I've done a bunch of 2.5 work but this is my first 3 liter but I can't say anything has been this disconnected from causation for all the codes I got. Sorry I don't have more but for 30 min of your time check out the Banjo bolts just to see. May get lucky. Best of luck!
Also, I'd also considered I'd jumped a tooth or installed the chain improperly since it seems timing related but AVCS has a huge impact to timing. One of the cheap things to do is data log with Torque or BlueDriver and see how your timing is advancing. It may at least confirm that timing is you cause of the misfires or you may see something in the fuel trims.
 

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Discussion Starter #14
Also, I'd also considered I'd jumped a tooth or installed the chain improperly since it seems timing related but AVCS has a huge impact to timing. One of the cheap things to do is data log with Torque or BlueDriver and see how your timing is advancing. It may at least confirm that timing is you cause of the misfires or you may see something in the fuel trims.
Will take a look at that, I have a cable coming for FreeSSM and will toss that on my winxp netbook, so maybe will be able to see a bit more as to what is going on.
 

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Will take a look at that, I have a cable coming for FreeSSM and will toss that on my winxp netbook, so maybe will be able to see a bit more as to what is going on.
You've probably tried but disconnect the battery and clear the codes. If it runs good after that then it point's to a learned fault and likely avcs. It's 1.5 hrs and a bit of a knuckle buster but a compression test is always worth it. I bought mine with a blown engine assuming the head gasket. I was always planning on rebuilding but went through the basics before i pulled it. Ended up being low compression in cylinder 2 that was due to a blown out valve. This was all before my Avcs issue post rebuild. Overall they are really solid motors but just complex when diagnosing codes. If all else fails try to find a subaru specialist (not dealer) to diagnose. They are a bit of a special breed, typical mechanics and dealerships are usually too lazy for a proper diagnosis.
 

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Discussion Starter #16
Have cleared the codes by battery post removal, and by clearing codes via ODB scanner. Since it started running right the other day I have ran it in the driveway I have not had codes come back. I am going to take it out this weekend and drive it hard locally to see if I can make it do something odd. But this thing is going up for sale this weekend, I just need it gone.
 

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Have cleared the codes by battery post removal, and by clearing codes via ODB scanner. Since it started running right the other day I have ran it in the driveway I have not had codes come back. I am going to take it out this weekend and drive it hard locally to see if I can make it do something odd. But this thing is going up for sale this weekend, I just need it gone.
Good luck! You might also check all the ground wires (main to battery, and one on each head to the frame rails). Bad grounds will cause misfires on subi's all day. If it's worth an oil change to you you can run sum seafoam through the crankcase for a few miles and dump it. From my rebuild I will say there are lots of small oil ports on the head that feed the avcs and cams and if you're got crud built up it could lead bad AVCS readings and timing. Hopefully it either cures itself or you get out from under it!
 

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Discussion Starter #18
Hopefully it either cures itself or you get out from under it!
Yeah, that's where I'm at. I have been unable to make it run bad the past few days, so it's going up for sale rather cheap.

Just wish the tires and rims would fit the wife's new Eclipse Cross :(
 
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