thatswhatshesaid Posted January 17, 2008 Share Posted January 17, 2008 So...my EJ25 is running like poo poo. - 2000 Outback (EJ25) with auto tranny - 135k miles - I've owned the car for the last 8k miles - maintenence before that is not well documented, so...? It all began about 1k miles ago (at the beginning of a 900-mile road trip), with a slight hesitation on hills, and a backfire every now and then. I had to finish out the trip. so now I'm back, I've driven it two more days and the symptoms are much worse. Backfiring happens in every gear below 3k RPMs. Above that, it smooths out, but still lacks the power it used to have. I have looked for vacuum leaks, but to no avail (I haven't done the propane test). Apparently there is no EGR valve, so that's out. When it starts to run roughly, the CEL flashes. It idles normally, but any more load than that and it runs badly. So here's what I'm thinking (let me know if I'm wrong): - PCV? I'll grab one tomorrow - it's 5 bucks and it probably needs it anyway. - Bad plugs/wires? If the plugs have carbon build-up, are the wires toast too? And how the flip can I get to the plug on cyl. #4? Any other ideas? Thanks, - Tyler Quote Link to comment Share on other sites More sharing options...
screwbaru2 Posted January 17, 2008 Share Posted January 17, 2008 Good place to start the pcv. Most don't get changed often enough. Check the hose(s) for flow. Or if they feel really hard like brittle replace em. The #4 plug take out or move aside the washer tank 2 bolts and a elect. connector or 2. You'll have all the room you need. Also do it with a cold engine. Alum. threads are easy to strip when they're hot, you can start one cross threaded and get enough turns on it you think your safe. After you toqure her down she never comes out again. Also go with subaru parts for the ignition some soobs are really fussy about those parts. Wouldn't hurt to check / change the air filter. I usually take out the air cleaner box for access to plugs 1 & 3, clean the box and replace the filter. Quote Link to comment Share on other sites More sharing options...
EVOthis Posted January 17, 2008 Share Posted January 17, 2008 Well first I would hook up a scan tool to it and see exactly which/ how many cylinders your dealing with.... Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted January 17, 2008 Share Posted January 17, 2008 Has the timing belt been replaced on this vehicle and has the valve lash been adjusted? If not, both are way overdue. The timing may have jumped a tooth on one of the cam sprockets. If the belt breaks it will likely bend valves and possibly ding pistons. That engine uses solid lifters with a screw and locknut adjustment for valve lash which is pretty easy to do. If any valve(s) are not closing all the way you can get misfire. how the flip can I get to the plug on cyl. #4? The plugs on that vehicle ('00obw - i have one too ) are easiest to do if you remove all the air intake snorkus stuff (pretty easy&quick to get out), remove the washer fluid tank, and optionally remove the battery. Plugs for that engine should be NGK spark plugs and OEM spark plug wires from a Subaru dealer or some say magnecor works very well. Anything else used on a soob can be the source of misfire. Engine could also be really carboned up, a good seafoaming sucked through the fuel pressure hose connection at the top of the intake manifold could be helpful. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted January 17, 2008 Share Posted January 17, 2008 You need new spark plugs and wires. Use OEM NGK plugs only and Subaru or Magnecor wires only. Unlike other Subaru engines, the EJ series are super picky with these items. Of course the proper way to diagnose is to have the CEL read and let us know exactly what it is. This is definitely not your PCV - but it's time to replace that as well, get one from Subaru. Hopefully the timing belt has been replaced? With the maintenance history not known you are 35,000 miles past due for a timing belt on a car that experiences serious internal engine damage if the belt breaks? This is an interference engine, fi the belt breaks bad stuff happens inside. I'd start planning ahead for that as soon as you can. Quote Link to comment Share on other sites More sharing options...
OB99W Posted January 17, 2008 Share Posted January 17, 2008 Agreed, get the diagnostic code(s) read (there may be more than one), and get back to us with any and all of them, not the code definitions. Example: code P0302, not "Cylinder 2 Misfire Detected". By the way, the "backfire" mentioned is more likely "afterfire". As you might expect, backfiring is when the mixture gets ignited in the intake; afterfire is when there's sufficient unburned fuel in the exhaust to be ignited there. True backfire doesn't tend to happen with fuel-injected systems. If it's really backfiring (intake), that can lead to damage of things (such as sensors) there, which could rapidly make the symptoms worse. An overly-rich mixture could be the cause of afterfire, but a lean mixture can be the reason as well since it can lead to misfire. Ignition problems and other causes of misfire can also lead to afterfire. Since the problem came on suddenly and progressed rapidly, I'm not inclined to solely suspect plug wires -- they don't tend to fail like that. They could be a contributing factor, so it's not a bad idea to replace them, especially since the maintenance history isn't known. I was somewhat inclined to suggest suspecting bad fuel, and a partially restricted fuel filter, but smooth running above 3k ... Hmmm, does the "not well documented" maintenance history mention oxygen sensor? As already has been mentioned, don't ignore the timing belt. Quote Link to comment Share on other sites More sharing options...
thatswhatshesaid Posted January 17, 2008 Author Share Posted January 17, 2008 I know the difference between "afterfire" and "backfire". It's definitely coming from the intake. And the previous owner assured me that the timing belt was replaced, but who knows with some of these crazy folks... Thanks for the help, guys. any other input on the matter? Quote Link to comment Share on other sites More sharing options...
idosubaru Posted January 17, 2008 Share Posted January 17, 2008 any other input on the matter? you need to read the codes, there are dozens of other possibilities... advanced auto parts, autozone and other places read the codes free and the OBDII scanners are now available for chump change $50 or less, so best to start there. Quote Link to comment Share on other sites More sharing options...
OB99W Posted January 17, 2008 Share Posted January 17, 2008 I know the difference between "afterfire" and "backfire". It's definitely coming from the intake.[...]Okay; I went into the discussion of backfire and afterfire because many people, including pros, use the term "backfire" incorrectly, and because it's unusual on injected engines. If it's truly backfiring, then the likelihood of timing issues is increased. Verifying that the timing belt hasn't jumped becomes even more important, because if it's done that once, it's likely to do it again, leading to possible internal engine damage (which may have already happened). Also, as I mentioned before, explosions in the intake don't do anything good. I'd suggest running the engine as little as possible until the timing is inspected, even if that means not getting the codes read right away. If the timing is good, you can relax while driving to Advance, AutoZone, etc. Quote Link to comment Share on other sites More sharing options...
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