Macdaddy911 Posted February 26, 2016 Share Posted February 26, 2016 Hey all, I think I may have a misfire or just a boost leak but I'm not sure. The car is a 06 outback xt 5mt with 155k on it. I recently put new NGK plugs in it trying to alleviate the problem but it's still there. It only happens when you the engine is under heavy load. I'd assume a misfire would be noticeable at basically all engine speeds and not just under heavy load. This cutout happens repeatedly when I'm at WOT. It basically cuts out for a second and then goes for a couple more and then cuts out again and it will continually do this while the accelerator is down. If I gradually ease into it there is no issue with acceleration. Is it possible that you could have a boost leak and wouldn't notice it until I was at higher psi or is this a misfire? I'm not really sure what to check at this time. I plan to try and do a leak down test to see if there is any boost leak but I haven't been able to do it yet. Any help would be appreciated. Link to comment Share on other sites More sharing options...
762x39 Posted February 26, 2016 Share Posted February 26, 2016 I had the same issue a while back and was pulling my hair out trouble shooting all avenues, Vac leaks, injectors, coil packs etc. I finally gave up and brought the XT to my regular auto shop. Finally the phone rang and I was expecting the dreaded call when all it turned out to be was a cracked porcelain on the #4 spark plug. The only thing I was too stubborn to check because I had changed them just 3500 miles prior. I kept the spark plug as a souvenir and a reminder that sometimes you need to back up and check the small things before you start pricing out a new short block. That's the end of my anecdote, hope its an easy fix for you. Are you getting a CEL? If not, you could pop the coil packs off and try to look around the plugs with an inspection mirror. When I cracked my porcelain, I didn't get a CEL/misfiring unless I really pushed the car, it would come up under conservative driving conditions. With the cracked plug, it would really only misfire once the turbo started to spool up. I would definitely stay out of boost until your problem is remedied. Link to comment Share on other sites More sharing options...
Macdaddy911 Posted February 26, 2016 Author Share Posted February 26, 2016 No CEL's, did a leak down and didn't find anything of concern. I have maybe 200 miles on these plugs but I didn't check the gap like a rookie ha. I assumed they were good because I bought the ones suggested that were supposed to be pre gapped. I guess I'll pull these out over the weekend and check to see what gap they are at. The NGK iridiums are supposed to be at what gap exactly? If this doesn't fix it I'm not sure where to go from here. Dealer wants 450 plus tax for new coil packs. I don't know if there are some that are cheaper online that are trusted. Link to comment Share on other sites More sharing options...
762x39 Posted February 26, 2016 Share Posted February 26, 2016 All of the purists here will say "OEM COIL PACKS ONLY!!" with no irrefutable evidence to prove why one will be less reliable than the other. I have had several tuners tell me to just replace them as they go with anything that is available, they either work or they don't. I have done just that. At this point Ive probably got 4 different brands coil packs hanging onto the block but its still churning out reliable stage 2 power levels every day for countless miles now. But worry about the coil packs if the plugs don't remedy the issue. Improper Gap sounds like it could be the culprit. I don't recall the Gap off the top of my head but its probably in the owner's manual. Good Luck! Link to comment Share on other sites More sharing options...
sketron1 Posted February 26, 2016 Share Posted February 26, 2016 I've got the same issue, more or less. I even had the tactrix and laptop plugged in trying to see what's going on. Looked like a saw tooth curve at wot. I'll be following this thread, I'll post one I figured mine out. Link to comment Share on other sites More sharing options...
Max Capacity Posted February 26, 2016 Share Posted February 26, 2016 I think the plug gap is .028 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
Macdaddy911 Posted February 27, 2016 Author Share Posted February 27, 2016 Got it all figured out. Turns out the old plugs were on their way out, which I knew so that's why I had a misfire before and after I took the new plugs out it turns out they sold me one wrong one so after I replaced that one with the correct plug it's all taken care of. Easy solution, just to stubborn to take those bastards out again haha. Link to comment Share on other sites More sharing options...
762x39 Posted February 28, 2016 Share Posted February 28, 2016 I know the feeling! I also Know the instant feeling of relief you must have felt when you realized that it was a cheap fix! Just a PITA! You should be charging them Labor! I'm happy to hear that all is well. Link to comment Share on other sites More sharing options...
Macdaddy911 Posted February 28, 2016 Author Share Posted February 28, 2016 I know haha, that'd be awesome! Yeah, so glad it wasn't something more involved. Now to find a tuner. Link to comment Share on other sites More sharing options...
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