Cylinder misfires or bad injectors, please post here.

we took the head off that side and tried out the valves ourselves and they were fine. spark plugs, coils, injectors and such have also been replaced. any chance it could be ecu or a wire harness?

What do you mean "tried out the valves"?

We took the seats and springs off of one on the intake side and one on the exhaust side and slid them back and forth to see if they were grabbing or bent at all

And I'm assuming the clearances are good on all of them?

 

I had two exhaust valves in #2 go bad and 1 in #4 go bad, so you have to check them all.

Ya the clearance is good on all of them. This past summer we took the engine out and replaced all the valves, the cylinders, and bearings

'97 outback Misfire on 1 & 3, did a compression test and have 180 PSi on both cylinders, plug wires are subaru OEM and a year old..

 

Coil pack has signs of burning where the plug end slipped too far off the boot but that's for cylinder 4 and I don't have misfires on those.

 

So I'm left with, replacing the coil pack (tested within spec) or move the injectors around.. but seeing as I have 252,250 miles how much more can I expect the injectors to flow nicely?

Are you the original owner? If not, then the injectors may have been R&R'd at some point in the lifecycle. If you have another vehicle, pull the injectors and send them to Witchhunter for cleaning/flow-balance-testing. If they test bad, then, you'll know which if any to replace.

 

They can be a biatch to pull, but I've found WD40 or Kroil with some initial twisting to loosen everything helps, plus a good slip-wire through the hole and pull while twisting gets it done.

Nope not the original owner.. but funny thing is it haven't happened again anymore yet.. I do know the tube from the intake manafold to the BPT was clogged and I had a P0400 code but I cleared that out and the EGR pipe to the head.

2005 Outback XT Limited 5MT

 

Been experiencing PO302 since 107k miles . Changed plugs and it went away. Was fine until recently, 111k miles. Swapped 1&2 spark plug coil, PO302 code came back after 100 or so miles. Put SeaFoam in the tank, again back after about 100 miles. That was this morning. I cleared the code and drove to work. Stopped to get gas at Exxon and car would not start the first time I tried to start it. Tried again, car started but had a hell of a time running. I had to keep the RPM's up to keep it running.

 

I /was/ going to swap the injectors tonight. Is there any point in doing so now or should I skip to a compression/leakdown? I'm terrifies this could be a valve or ring. The previous owner had kept great care of the vehicle, as far as I know. I'm talking oil changes every 3500 miles.

 

EDIT: I forgot to mention, once I got to work (1.5 miles down the road) it idled fine, purred like a kitten.

Edited May 21, 2013 by ScoobyDoo94

Need to do a leak down/ compression test. That will tell you the most.

 

Mine lost an exhaust valve at 150K. Bought new and meticulously maintained.

 

When mine finally failed after fighting some misfires it would not really run well at all below 2K. Drove it home highway miles and kept it above 2K

 

If I went below the 2k it would not stay running.

 

30 PSI in one cylinder. Block and pistons were perfect.

 

Installed a new motor anyway as engine had to come out to repair heads

Edited May 21, 2013 by Scooby2.5

Mine has been maintained well since the day I got it. Beyond doing all the oil changes and scheduled maintenance when scheduled, there's not much else you can do. Washing and waxing the car every month doesn't keep the motor from eating itself.

 

Sadly I suspect a bad valve in your case, ScoobyDoo. There's speculation that bad timing on the factory tune is the cause of these valve failures, or that the valve clearances are set too tightly from the factory to reduce noise.

 

Mine went at around 95,000 miles. Given the work involved in repairing these engines, I wish Subaru would have paid a little more attention and designed them for longevity.

If it is a bad valve, would subaru cover that out of warranty? Especially seeing how prominent this issue is?

I doubt it. But you could always try

I highly doubt it. But look on the bright side, you'll get new head gaskets

So I drove it home after work, to the local Giant Eagle, and on the highway, and through the backwoods to get to my house. Only a single miss was heard. Car started up perfectly fine, idle went from 1k to 1.5k and sat and idled perfectly. Upon driving, it had power, sounded fine, and when I checked my OBD reader when I was home, not a single code came up, pending or confirmed.

 

What the hell guys?

 

I'm swapping number 2 & 4 injectors and going from there.

I could clear my CEL and the misfire wouldn't come back for several days. The car seemed to run fine, idled mostly OK.

 

It held compression just fine but the valve clearance was next to nill. The valve works it's way up in the valve seat, and when it heats up it expands and doesn't seal properly.

 

My injectors were swapped too.

Awesome... I'll swap the injectors and hope. I'll report back when I have results.

Swapped it over, started it up. Sounded fine. Checked my OBD app and one code was pending. PO302. [insert expletive(s) of choice here]. Ill talk to the dealer tomorrow and start driving my Cougar until I have the money to get new/rebuild the valvetrain.

 

At least I'm mechanically inclined..

I think mine was about 30 hrs labour.

 

With head refinishing, a new clutch, starter, all new hoses, timing belt, tensioners, etc... the bill was around $8K

Im paying 9k for my car alone. I just got the freaking thing at 105k miles. I'm seriously considering getting rid of this thing. Its been nothing but problems.

 

Maybe I can get some pity from the dealer and he'll at least pay for half of the valve/head job.

P0304 car has 226000 miles. I have had to replace 1&3 coil packs, so I'm hoping it's just that.

p0304 and p0302 today. The ignition coils on that side are original, so hopefully this will be just a hundred dollar fix.

cyl 3 misfiring on 05 LGT with 130,000kms ...my tech swapped coil and the injector and it runs much nicer now...the spark plug was white...I am not sure how long this cylinder has been misfiring for as I hardly noticed it myself to be honest but I am not a mechanic and I expect engines and cars to rumble but it was clear as day to the tech...apparently the coil within the injector failed or died and the plates in the coil pack were seperating and was only working at times, so both were swapped with used parts that tech knows are good and should last..

 

So even though now my car is running great now, I am afraid that it may have caused damage elsewhere such as the valves or other....do I need to worry about any of this, run anymore tests or go look for more is it a waste of time and money?

 

Thanks!

Edited June 26, 2013 by crankshift

oh by the way no check engine light came on whatsoever for me but the day I took it in to the shop it came on for him with the cyl 3 misfire code...I have got CEL for intake manifold error once or twice many many months ago and just cleared the code and it never came back....it may have came back once (a second time) more several months later and we would have cleared it again and still hasnt returned to date..

 

Thanks!

I found a local tuner that tuned my car for me and sorted out a few things for me and got my car running good. Shortly after my car started bucking from around 2k-2500rpm with the boost between +- 5psi from 0. I contacted my tuner and he took a look at it and we datalogged some and he couldnt find anything but a very lean condition happening when it started bucking and he said it felt like a misfire for sure.

 

We popped the hood and looked around for a few and I have an sti UP that was on the car when I bought it that has no heat shield. I had noticed before when i was changing spark plugs that the connector lock was broken off on the coil right by the UP and I assumed it was just brittle from heat. My tuner said he thinks its a cracked coil at that cylinder from the extra heat that isnt being blocked by a shield and its shorting out somewhere and so the car is detecting its sparking but the spark isnt making it to the plug at times.

 

He cleaned up a little bit of knock for me and sent me on my way and usually after I put a new tune on the car doesnt want to idle or run well for a few but this time it lasted for my 20min drive home and and still not idling. It will idle fine when I really get on it then let it idle down but if its idling and I barely touch the throttle it will jump the rpm as it should then it drops idle super low and either shakes for just a second and idles back up or it just dies on me. I ordered a new coil to try that and im going to replace that connector when I find a replacement.

 

Anyone heard of anything like this or have any advice for me I would be more than happy to read about it.