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04 Outback Cranks, fires, sputters, dies, bad communication with ECM


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Sorry.. I'm sure this is covered somewhere, but the system won't let you search 'ecm'.. not enough letters...

 

Our 04 Outback, 2.5L, auto, AWD, wagon, 140k ish.  Started missing last week.. became worse and worse.  Had trouble pulling hills...  helped to shift into 3rd or 2nd to spike the rpms....   Became to bad to continue and I parked the car. 

 

Now.. it cranks, back fires sometimes out the back, sometimes up thru the throttle body.  This afternoon I could not get it to start at all.... 

 

AND... the biggest clue I guess...  my scan tool would not come on when plugged into the obd port.  Just a blank screen at first. Then after bit it flickered on, then off.  Once it stayed on long enough to read the codes, but it only showed p0032, which it's shown for years, even after I replaced the 02 sensor. 

 

So where do I start here...  is the ECM plug and play for a swap in my car... it's an 03.  Any likely culprits for something shorting out the ECM?  I saw another post similar which turned out to be a corroded air pump sensor?

 

Ideas?  

Thanks!

Mike

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Not sure why the scanner isn't working... but with the backfires, I would look at the timing belt,  if that is in time then , I would swap out the cam and or crank sensor with  known working ones. Then check compression ,it could be valve lash... anybody checked the valve adjustment EVER ? Common on this motor for the exhaust valves to go tight and burn the valve seat. That shouldn't keep it from starting though, just run like shxt.    

Have you tried that scanner on another car ? 

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timing belt was replaced about 20k ago... guess it could be a problem again.     I just tested the scanner in the Camry... works 100%.  Today, I can't get it to show in the Subie at all.

 

We're looking for something that went bad quickly, but not instantly.  There was a miss for a week or two, mainly in low rpm moments, just prior to a down shift as you headed up a hill.  That became more of 'stutter and sputter moment' as it got worse.

 

My daughter had the car out and it over heated on her....  I confirmed the overheating issue and swapped out the thermostat, which fixed the over heat, but the sputtering continued to get worse.  I made one 15- 20 mile drive with it, for which it was super hard to get started, and the sputter became what I'd call severe.  After getting back, I haven't gotten it start but once, now it won't start at all.  The scanner at first yesterday came on and off a couple times when plugged in, and actually scanned once, as mentioned above.  Then it went blank.  Today, i can't get it so come on at all in the car.  

 

I checked all the fuses, all good.  Can't find any loose wires anywhere, tho I don't really know where all to look.  I guess that would be everywhere.  Right now, I'm letting it sit with the batter disconnected to see if that might 'reset' the ecm and at least getting it talking to the scanner.  

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Not sure how hot it got...  my daughter was driving it and I think she pulled over due to the sputtering on the hill she was pulling more than the overheat, but it was def boiling over at the jug.  She was 1/4 mile from home, all down hill so once it cooled off I had her pull out get up to speed and put it into neutral, drifted into the drive and shut it off.   I added fluid and took it for a drive.... watched it heat up to 3/4 range and took it home.... lower hose cold, upper hose boiling....  swapped out the thermostat and she ran pegged at at the middle.  Also...  ran pretty good... only a slight miss...  which over the next 2 days and maybe 100 miles  turned into a sputter and then the current non-starting condition with no ECM communication.

 

I hooked back up the battery and there was no change in the status.

 

i can pull a plug and see what it looks like....  I'm looking for fouled plugs, I assume....

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Ok... pulled one plug...  it's a mess.  Also, the gap is about .060 which seems way large.   Obviously I need to swap out the plugs to diagnose...

 

I assuming with the over heating there is a concern that the head gasket may be blown...    car ran perfectly cool.  There is no frothiness in the oil, and no sludge/ brown in the fluid jug...   coolant is still nice and green in the jug...

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  Yes ,i'm wondering about the head gasket... overheating gets them more times than not. oil and water do not mix on this motor when the head gasket is shot. Car will run cool until you lose enough coolant. I'm also still thinking valves . Compare all the plugs to see if any are different.  By the By, remove and clean your grounds , both ends ... clean and tight.  Not just the battery but the smaller grounds as well. .. could help with your scanner and if bad enough could cause your miss ... but I doubt it.  I still think there is a compression check coming in the near future.

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Could head gasket failure lead to fouled plugs?  Mine just looked really old, and now I've gone out and bought new ones, and the gap should be .044... the one I took out is 060.  I going to replace those and the plug wires as soon as I get done with my incredibly delicious Sheetz salad....  I'll post the results....    of the new plugs and wires, not the salad.

 

Thanks!

Mike

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sorry... thought it might make someone smile.  So I did buy NGK plugs...  carquest wires were all they had.   Old plugs were AC Delco.

 

So....  looks like a case of misdirection.  New plugs and wires are in, and the car started right up, and idles smoothly.  The scanner, however, still can't see the CEM.

 

I'm gong to take the car for a test drive.  If it looks like it's running okay, I'll take a longer run of about 20 miles home which will get it nice and hot.  I'll post the results after that.

 

If anyone has any other thoughts on the CEM communication issue, let me know.

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It is a cheap scanner, but I've used it on this car for years....

 

So the test drive went great...  drove 30 miles or so, no miss.  No problems at all.  Back his usual great running self.  So I'm going to consider the sputtering issue solved for now.

 

As a note for others, I find it interesting that the issue came on so fast....  from an intermittent miss to not starting in 2 days and a 100 miles.  Problem was most likely plugs from the condition of them, but may also have been the wires.  If you're doing plugs, just do wires at the same time since you'll have them out anyway.  And take out the windshield washer fluid jug to access the driver's side plugs... super easy.  Same for the plastic box under the air intake hoses on the passenger side.

 

Thanks for the help and for pointing me toward the plugs.  I'll start a new thread for the Computer Communication issue under the title '04 Outback no communication Computer to Scanner.'

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