samuel082799 Posted November 24, 2019 Share Posted November 24, 2019 I got a cylinder 2 misfire code the other day, and was noticing ruff idle earlier that morning. So I whet through a diagnosis to try and find the source of the misfire. I first did a ghetto leak down test and I could here a slight leak from what seemed to be the turbo inlet which is pretty deteriorated, but I don't think that is the cause of the misfire. Then I pulled the injectors to take a look at them and they looked fine they weren't clogged or leaking. Then I pulled all the spark plugs which only have like 8000 miles on them and they all looked fine. Then I swapped coils from cylinder 2 and 4 since last time I had a misfire it was the coils. I then started it up and plugged in romraider and seen that the engine is still missing on cylinder 2 only. So my question is we're do I go from here, the mis is only at idle when I rev it up and hold it there is no misfires. Like I said I do have romraider so if there are any other parameters I can look at to help me diagnosis the problem let me know. Also the wiring harness is new. Thanks in advanced. Link to comment Share on other sites More sharing options...
Max Capacity Posted November 25, 2019 Share Posted November 25, 2019 A good compression test would be next, followed by a leakdown test on that cylinder. 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...
xt2005bonbon Posted November 25, 2019 Share Posted November 25, 2019 well, if the misfire is staying on #2, and you've already checked the injector, spark plug, and coil, then next culprit could valve clearance or piston ringland failure. Link to comment Share on other sites More sharing options...
gkinslow Posted November 25, 2019 Share Posted November 25, 2019 (edited) well, if the misfire is staying on #2, and you've already checked the injector, spark plug, and coil, then next culprit could valve clearance or piston ringland failure. But he didn't really check the injector or spark plug. (assuming I'm reading that correctly) Swap these one at a time (as you did the coil pack) and see if the misfire follows. If it stays in cylinder 2, then you are looking at valve clearance or ringland issues. Edited November 25, 2019 by gkinslow Link to comment Share on other sites More sharing options...
xt2005bonbon Posted November 25, 2019 Share Posted November 25, 2019 You know how it goes though. But let's stay optimistic . Link to comment Share on other sites More sharing options...
Max Capacity Posted November 25, 2019 Share Posted November 25, 2019 Who's the first to say ynansb ? 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...
xt2005bonbon Posted November 25, 2019 Share Posted November 25, 2019 I mean, still a moderate chance of valve clearance issue. But yeah, if that is not it, then y.... Link to comment Share on other sites More sharing options...
ttnio Posted November 26, 2019 Share Posted November 26, 2019 well, let's hope the heads don't have to separate the block. if so, ynansb. Link to comment Share on other sites More sharing options...
samuel082799 Posted November 26, 2019 Author Share Posted November 26, 2019 **Update** I am doing a compression test tomorrow, I pulled the the timing cover and the timing is perfect. I cleaned the maf sensor. I swapped plug 2 and 4 and no change. I took it for a drive with the laptop out and the car runs absolutely perfect with the exception of idle. The computer shows no misfires while driving, just at idle. I got out a stethoscope and listened to the injectors, and injector 2 is a little bit noiser than the rest. Tomorrow I'll probably also swap the injectors and see what that does depending on how the compression test goes. What is the easiest way to disable the fuel pump for doing the compression test? Link to comment Share on other sites More sharing options...
Max Capacity Posted November 26, 2019 Share Posted November 26, 2019 I believe there's a fuse for the fuel pump in the underhood fuse box. 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...
Berge56 Posted November 26, 2019 Share Posted November 26, 2019 You can floor the gas pedal while cranking the car over for the compression test. Eager to hear the results. My 2 guesses are as follows: If it's low compression most likely a ring land. If it's zero compression, burnt valve. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted November 26, 2019 Share Posted November 26, 2019 yep. Just floor the gas pedal while cranking, or remove the fuel pump fuse. Do you recall if the misfire occurs at warm or cold idle, or both? As I've shared several times on this forum, both of my cars suffered from a tight exhaust valve. I just had to readjust the clearances and I was good to go. If caught early, then no burnt valve. Now, as previously said, if clearances are fine, then ringland issues may be next. Link to comment Share on other sites More sharing options...
dgoodhue Posted November 26, 2019 Share Posted November 26, 2019 As I've shared several times on this forum, both of my cars suffered from a tight exhaust valve. I just had to readjust the clearances and I was good to go. If caught early, then no burnt valve. How did you diagnose a tight exhaust valve? Link to comment Share on other sites More sharing options...
xt2005bonbon Posted November 26, 2019 Share Posted November 26, 2019 I checked the valve clearance and both cars had 0mm of clearance on one exhaust valve. Both cars were idling a bit rough. The misfire counts were non zero during idle. Usually, this issue would end up in rough warm idle, not necessarily at cold idle (valve stem expands at operating temp, thereby reducing the clearance -- so if you have zero clearance to begin with, car's gonna run poorly when warmed up). But then again, one of my cars still had poor cold idle too. I thought it was ringland until I checked the clearance and fixed it. Been 35K now and she runs good still. Link to comment Share on other sites More sharing options...
gkinslow Posted November 26, 2019 Share Posted November 26, 2019 I checked the valve clearance and both cars had 0mm of clearance on one exhaust valve. Both cars were idling a bit rough. The misfire counts were non zero during idle. Usually, this issue would end up in rough warm idle, not necessarily at cold idle (valve stem expands at operating temp, thereby reducing the clearance -- so if you have zero clearance to begin with, car's gonna run poorly when warmed up). But then again, one of my cars still had poor cold idle too. I thought it was ringland until I checked the clearance and fixed it. Been 35K now and she runs good still. What were the results of your compressing tests? I'm betting this gets called a "burnt valve" and results in an unnecessary rebuild fairly often. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted November 26, 2019 Share Posted November 26, 2019 I did not do one. However, I did do cold leakdown tests (you're supposed to do them warm). And they both yielded great results! (like 2.5% on one and 5% on another I think). So you can imagine how I was like, "OK that's it. It is rings or something then." But one day, I felt to check the clearance and bam. That was it. But again, it is not always that 'easy'. Like right now, I know my 05 needs a block, which I am going to purchase real soon (going through a gallon of oil in 2K eeeasy! ). Link to comment Share on other sites More sharing options...
samuel082799 Posted November 26, 2019 Author Share Posted November 26, 2019 Do you recall if the misfire occurs at warm or cold idle, or both . It doesn't seem to misfire cold, which I assume is because the car is not at idle rpm. Once the rpm drops to 800 then it starts misfiring, and it seems to get worse as it warms up, but the problem is just at idle. Warm driving around no misfires siting at a light misfires. Link to comment Share on other sites More sharing options...
samuel082799 Posted November 26, 2019 Author Share Posted November 26, 2019 I also consume a lot of oil, but I think it is coming from my turbo because I have a crawford air oil separator. My whole intake system past the turbo was full of oil all the way to the throttle body. I have a spare vf40 that I'm going to rebuild and throw that in, and I also have a block that I was building, but hoping my engine would last till summer so I can swap them while it's not raining. My only other vehicle is my motorcycle so I'm probably going to have to miss a few days of school because I don't want to ride in the rain. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted November 26, 2019 Share Posted November 26, 2019 Yeah. Usually, cold idle misfires are associated to ringland issue (even more prominent when it is really cold out there since it is even harder for the piston/rings to provide a good compression in the cylinder after startup). My misfire problems showed 98% of the time at idle too. Drinking oil huh. Do you see big puff of smoke under boost? Have you checked the exhaust side of the turbo? if dry, then turbo may be OK. Link to comment Share on other sites More sharing options...
samuel082799 Posted November 26, 2019 Author Share Posted November 26, 2019 Drinking oil huh. Do you see big puff of smoke under boost? Have you checked the exhaust side of the turbo? if dry, then turbo may be OK. I haven't checked the exhaust side and I don't see any smoke from the driver seat. All of the cases of ringland failure I have seen have tones of smoke coming out the exhaust, my exhaust is clear if smoke Link to comment Share on other sites More sharing options...
samuel082799 Posted November 26, 2019 Author Share Posted November 26, 2019 I might also mention that the car is not hard to start. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted November 26, 2019 Share Posted November 26, 2019 Well I mean, my 05 is running great too at the moment. Doesn't even have a rough idle. The turbo has been upgraded too and stuff. And I can't even see puff of smokes either. But the fact remains that I go through more than a gallon of oil per OCI . Last compression check reported 15% less compression on the driver side. Link to comment Share on other sites More sharing options...
samuel082799 Posted November 26, 2019 Author Share Posted November 26, 2019 Compression test is not looking good, I don't know exactly what this means yet, but I'll let y'all help me with that. In order 1 - 4 the cold compression test yielded 125, 50, 125, 105. I did two test on each cylinder just to double check. Is there anything else I should check while all the plugs are out. Will a hot compression test give me any more information than I already have? Link to comment Share on other sites More sharing options...
xt2005bonbon Posted November 26, 2019 Share Posted November 26, 2019 so yeah, you do have lower compression in #2. Now you need to find out if it is the rings or the valves. next, I would either do a leakdown test or valve clearance check. Link to comment Share on other sites More sharing options...
samuel082799 Posted November 26, 2019 Author Share Posted November 26, 2019 so yeah, you do have lower compression in #2. Now you need to find out if it is the rings or the valves. next, I would either do a leakdown test or valve clearance check. What is easier to do? And how? Link to comment Share on other sites More sharing options...
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