Jump to content


Welcome to Ultimate Subaru Message Board, my lurker friend!

Welcome to Ultimate Subaru Message Board, an unparalleled Subaru community full of the greatest Subaru gurus and modders on the planet! We offer technical information and discussion about all things Subaru, the best and most popular all wheel drive vehicles ever created.

We offer all this information for free to everyone, even lurkers like you! All we ask in return is that you sign up and give back some of what you get out - without our awesome registered users none of this would be possible! Plus, you get way more great stuff as a member! Lurk to lose, participate to WIN*!
  • Say hello and join the conversation
  • Subscribe to topics and forums to get automatic updates
  • Get your own profile and make new friends
  • Classifieds with all sorts of Subaru goodies
  • Photo hosting in our gallery
  • Meet other cool people with cool cars
Seriously, what are you waiting for? Make your life more fulfilling and join today! You and your Subaru won't regret it, we guarantee** it.

* The joy of participation and being generally awesome constitutes winning
** Not an actual guarantee, but seriously, you probably won't regret it!

Serving the Subaru Community since May 18th, 1998!

Guest Message by DevFuse
 

Photo
- - - - -

Misfiring 3 of 6 cylinders in a 2001 Outback H6??


  • Please log in to reply
18 replies to this topic

#1 sydeburn

sydeburn

    New User

  • Members
  • Pip
  • 6 posts
  • New York

Posted 26 June 2012 - 05:31 PM

I just bought a used 2001 Subaru Outback L.L.Bean, and the check-engine light is on due to misfiring in cylinders 1, 3, and 5 (right side only). I thought I was getting a pretty good deal even given the CEL risk, but the car is at the mechanic now and he is stumped and telling me I have to take it to a dealer service center.

This is a 6 cylinder with a timing chain. Plugs were replaced and computer reset and the light came right back on. There are no spark plug wires, and I read that the coil packs rarely fail. The engine runs smoothly and seems to have power, but since I just bought the car used so I'm not sure how much power is normal. It has 122k miles.

What could be causing misfires on one side of the engine only? Any ideas?

#2 Fairtax4me

Fairtax4me

    Su bah roo'n

  • Gold Subscribers
  • 8,774 posts
  • Charlottesburg, VA

Posted 26 June 2012 - 08:44 PM

Usually if one side is affected it's jumped timing. That should show up in a compression test. I've heard of the H6 engines having some issues with timing chain guides, but mostly at high (200k + ) mileage.
Are there any other codes besides the codes for misfires? Anything at all?

edit: I didn't read the whole post first.

Could be a sensor issue, plugged cats, even a bad intake gasket.
Did the mechanic do a compression test?

Edited by Fairtax4me, 26 June 2012 - 08:46 PM.


#3 sydeburn

sydeburn

    New User

  • Members
  • Pip
  • 6 posts
  • New York

Posted 26 June 2012 - 11:51 PM

No compression test, and I'm kinda kicking myself for not asking for it, since he had the plugs out.

He didn't say there were any other codes, but I'll call in the morning to confirm and post here.

Could the timing be off on one side if the the car is running smoothly?

#4 grossgary

grossgary

    Elite Master of the Subaru

  • Members
  • 19,837 posts
  • WV

Posted 26 June 2012 - 11:58 PM

simple test - swap cylinders 1,3,5 coil packs with the ones on the other side and clear the check engine light. if the cylinder misfires "move" with the coil packs then you know they are the issue.

a friend had this happen with his new to him 02 Outback H6. couldn't figure it out and i was out of town to further diagnose for him, ultimately a shop replaced two coil packs and it was fixed.

fuel supply issue as well may cause a lean condition on that side of the engine. not sure how the fuel pressure regulator works on H6's...i doubt you'll end up finding the issue there anyway.

#5 ShawnW

ShawnW

    Subaru Master Technician

  • Administrator
  • 12,931 posts
  • Denver, Colorado

Posted 27 June 2012 - 01:23 AM

I have seen people get fed up with replacing spark plugs on these engines after doing half of them and quit. Could have original plugs one side and new the other.

#6 bstone

bstone

    Certified Subaru Nut

  • Members
  • 804 posts
  • Falls Village, CT

Posted 27 June 2012 - 01:35 AM

I once poked around on this engine to see how I could change the spark plugs. I think the easiest method is removing the engine.

I second the idea of changing around the coils and see if the misfires follow.

#7 ivans imports

ivans imports

    1000+ Super USER!

  • Members
  • 2,947 posts
  • lumby bc canada

Posted 27 June 2012 - 09:31 AM

feul pump low output staving the one side i doubt timing had one of those engines with 380000kms no chain ishues i dont think it can jump phisicaly cant happen to many chain gudies cracked plugs or tracked coil boot or coils pluged into wrong harness conector

#8 sydeburn

sydeburn

    New User

  • Members
  • Pip
  • 6 posts
  • New York

Posted 28 June 2012 - 10:43 AM

Ok, here’s the update: the mechanic had already swapped the coils-- he said that was the first thing he tried. Sorry I didn't know that before. The code went away, then he took it for a 4-mile drive and the same codes came back. Cylinders 1, 3 and 5 misfiring. There were no other codes. I mentioned the timing on that side only and said highly unlikely and not worth checking since the car is running smoothly.

Below are the remaining possibilities I've culled from this and one other forum. Can any of these be ruled out, in your experience? And which are more likely than others? Remember that the engine is running smoothly and there are no other codes...

some fluke battery weirdness?

igniters?

a crankshaft/camshaft position sensor that's not providing a consistent firing signal?

O2 sensor? (assuming each side has its own)

fuel injectors messed up due to undercarriage pressure wash?

fuel pressure regulator? (assuming each side has its own)

fuel pulsation damper? (assuming each side has its own)

fuel pump?

#9 bstone

bstone

    Certified Subaru Nut

  • Members
  • 804 posts
  • Falls Village, CT

Posted 28 June 2012 - 11:02 AM

Did he swap the plugs also?

#10 sydeburn

sydeburn

    New User

  • Members
  • Pip
  • 6 posts
  • New York

Posted 28 June 2012 - 12:41 PM

Plugs were replaced.

#11 ivans imports

ivans imports

    1000+ Super USER!

  • Members
  • 2,947 posts
  • lumby bc canada

Posted 04 July 2012 - 10:03 AM

check where main harness plugs in for engine posibly water in conector or not pluged in all the way put a volt meter on + side of injectors and make sure all are geting full voltage to them check coil boots for tracks and what was plug gap set at have had misfires from to small of plug gap or tracked plugs /boots or intake gasket on that side i whould look for what thoose cly have in commen ingector grounds power diss and feul rail mabee feul pump has low output and not enuff feul is geting to the far side of engine i have a compleate h6 with harness on ground if need me to meshure anything

#12 sydeburn

sydeburn

    New User

  • Members
  • Pip
  • 6 posts
  • New York

Posted 10 July 2012 - 11:43 AM

I did end up taking this to a Subaru service center. They diagnosed the problem as "massive carbon build-up on one side of the head" and said they'd need to re-build the head to guarantee the check-engine light will go away.

So now the question is: who wants to buy a H6 Outback for cheap?

I can't afford to pay the Subaru service center for these repairs, and I don't have a place to do the repairs myself.

It's a 2001 LL Bean edition with no rust anywhere, 9/10 leather interior, 8/10 exterior (a few dings). 122k miles. Needs the check engine light addressed and front CV axles. Engine actually runs smooth. Transmission is smooth and shifts without problems. No fluid leaks. KBB private party value in fair condition is $6120. Asking $3500. Please PM me if interested.

Or if anyone wants to direct me to a more proper place to post this (since it's now basically an ad), please let me know.

Thanks again everyone for your input.

#13 grossgary

grossgary

    Elite Master of the Subaru

  • Members
  • 19,837 posts
  • WV

Posted 10 July 2012 - 11:45 AM

If you were closer I'd take it today....i'll look where you're located and see what I can't work out. Want to drive it here and fly home, LOL.
my username here @yahoo.com is my email, hit me up.

What part of NY are you in?

#14 john40iowa

john40iowa

    USMB is life!

  • Members
  • 218 posts
  • Ankeny

Posted 10 July 2012 - 12:32 PM

Have you considered giving the engine the Seafoam treatment. Looks to really work from the video.

#15 sydeburn

sydeburn

    New User

  • Members
  • Pip
  • 6 posts
  • New York

Posted 10 July 2012 - 12:38 PM

Car is in NYC (currently parked in Queens).

Re: Seafoam treatment-- I guess it can't hurt anything. Or can it?

#16 grossgary

grossgary

    Elite Master of the Subaru

  • Members
  • 19,837 posts
  • WV

Posted 10 July 2012 - 12:59 PM

Car is in NYC (currently parked in Queens).

Re: Seafoam treatment-- I guess it can't hurt anything. Or can it?

no if done properly. i guess if you dumped too much right into a cylinder you could hydrolock it and do some damage that way, but just follow directions properly.

it will *look* like something is wrong as it burns off and your neighbors will think you're burning your car for insurance and call the cops...it smokes LIKE CRAZY when you start dumping that into a running engine. but it's all normal, just act real cool like "it's supposed to be doing this, i am not surprised or moved" and you'll feel like James Bond. :headbang:

#17 ivans imports

ivans imports

    1000+ Super USER!

  • Members
  • 2,947 posts
  • lumby bc canada

Posted 12 July 2012 - 10:24 AM

i put propane and turbo on my 3.0 fixed the carbon problem right up i whould run a water line in and water the bugger wide open for a good drive a washer bottle works good with a small jet mabee 0.16-0.20 and feed it some water at wide open throttle

#18 bstone

bstone

    Certified Subaru Nut

  • Members
  • 804 posts
  • Falls Village, CT

Posted 12 July 2012 - 04:19 PM

Second the SeaFoam.

#19 Cougar

Cougar

    Elite Master of the Subaru

  • Members
  • 6,340 posts
  • Anchorage

Posted 13 July 2012 - 03:07 AM

Here is another product you might try mixing in the fuel. They have excellent products that work.

http://www.kanolabs.com/engCle.html




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users