commbubba19 Posted December 29, 2017 Report Share Posted December 29, 2017 I posted this up on the Facebook group but I'm aware not everyone here is on that page. Been having random rough idle on and off over the last few months. Picked up a bluetooth OBD reader with software to monitor. Nothing exciting for the last month. Perfectly normal engine reports. Yesterday, drove around for about an hour and then got gas and a car wash (touch-less at least) but the line was long. As I was waiting the idle started to become rough and vary enough to shake the car. A couple quick free revs didn't clear it up so I plugged in the scanner. Found that Cylinder 5 was reporting misfires and a lot of them. I then shut the car off and let it sit until I needed to move up in line. Upon start up it was immediately rough and I got a CEL for misfires on cylinder 5. It continued to be rough for about 15 minutes but then just cleared up and was perfectly smooth. Drove home as normal. Later that evening I pulled cylinder 5 and cylinder 4's spark plug to compare. As you can see, 5 is pretty messed up. A lot of build up from what I'm guessing is oil possibly from blow by or the PCV system. Since 4 is clean, I don't believe it would be the PCV but I'm not an expert. I've cleared the CEL and am going to make an appointment with Ford the next time this happens which based on that plug, should be soon. I'd be curious if anyone else has a dirty #5 plug. It's pretty easy to get to. Quote Link to comment Share on other sites More sharing options...
Mikula Posted December 29, 2017 Report Share Posted December 29, 2017 (edited) I usually say that is oil or fuel related but being only 1 cylinder is strange. any other engine i'd say the head gasket has an issue in the area of that cylinder, possibly letting coolant into the cylinder, but i don't know exactly how this motor was engineered. hell, i just learned the damn thing has an internal waterpump, so maybe someone else can step in here to help. did you pull any other plug to see if they look like this? or only the one that currently had the misfire? remind me again, is it tuned or stock? and what kind of mileage? Edited December 29, 2017 by Mikula Quote Link to comment Share on other sites More sharing options...
commbubba19 Posted December 29, 2017 Author Report Share Posted December 29, 2017 I usually say that is oil or fuel related but being only 1 cylinder is strange. any other engine i'd say the head gasket has an issue in the area of that cylinder, possibly letting coolant into the cylinder, but i don't know exactly how this motor was engineered. hell, i just learned the damn thing has an internal waterpump, so maybe someone else can step in here to help. did you pull any other plug to see if they look like this? or only the one that currently had the misfire? remind me again, is it tuned or stock? and what kind of mileage? I've ran it both tuned and stock for various periods of time. I've seen random puffs of blue and i've already added a qt of oil since my last change 5k miles ago. I've also added about 1/2 qt of coolant as the tank always seems to be below max level. I've never smelled coolant being burned and no leaks. 15k miles on it right now. I plan to change the oil Sunday. Obviously I can replace the plug and solve the problem temporarily, but if there's an issue with that cylinder like a head gasket issue or something else, that plug will eventually get fouled up again. So I'm thinking i'm going to leave that plug in as is and when the misfires return, bring it in and let ford dick with it. Quote Link to comment Share on other sites More sharing options...
Mikula Posted December 29, 2017 Report Share Posted December 29, 2017 (edited) I would definitely check other plugs and see what they look like. might tell you if its fuel quality, or running hot/lean. but in my opinion and my (not so) vast knowledge of automobiles, you shouldn't be having to put coolant in. wife bought her car brand new, i've been her oil change "specialist" since she got it. just flushed her coolant at 80k, but only once had to top it off, and that was last year at 65k. that's in central texas summers as well. i hope it isn't tune/exhaust related, or I will also be in for a treat in a few miles. I'm wondering if the tune or computer accounts for the exhaust pulling more air out and adjusts the a/f ratio. do you happen to have any tool or app or something to monitor air/fuel while you're driving it? Edited December 29, 2017 by Mikula Quote Link to comment Share on other sites More sharing options...
commbubba19 Posted December 29, 2017 Author Report Share Posted December 29, 2017 LMS doesn't data log but the information for the a/f is in the PIDS that SCT and HPTuners can pull. A tune wouldn't cause the oil fouling of the spark plug. That's a mechanical failure. Cause is the tricky part. Could be rings, valve guides, PCV, etc. Hence why I'm leaving the plug in there and driving it around until it throws a code again. At which point I'll see what Ford says. Quote Link to comment Share on other sites More sharing options...
Mikula Posted December 29, 2017 Report Share Posted December 29, 2017 (edited) personally, if it was me, i would pull plug 5 and swap it with a different cylinder. if #5 throws a code again, you have it narrowed down substantially. if #5 shows no signs after some mileage, then just get a new set of plugs and gap them properly. i was only mentioning a tune because ford loves to deny warranty claims based on any extra-curricular fart you do with a vehicle Edited December 29, 2017 by Mikula Quote Link to comment Share on other sites More sharing options...
WWWPerfA_ZN0W Posted December 30, 2017 Report Share Posted December 30, 2017 Valve cover gaskets and plug well seals are a common culprit for this issue on Ecoboosts. I expect the same here. Quote Link to comment Share on other sites More sharing options...
todd92 Posted December 31, 2017 Report Share Posted December 31, 2017 How would a leaking valve cover gasket or plug well seal get oil into the combustion chamber? Quote Link to comment Share on other sites More sharing options...
1004ron Posted December 31, 2017 Report Share Posted December 31, 2017 How would a leaking valve cover gasket or plug well seal get oil into the combustion chamber? I don't think that's what was being suggested, but rather that the oil in the plug well would cause electric arcing and plug misfires. Quote Link to comment Share on other sites More sharing options...
enigma-2 Posted December 31, 2017 Report Share Posted December 31, 2017 Possibly a malfunctioning injector. Head gasket would not be intermittent. Injector malfunction would run the cylinder cold, allowing oil to accumulate. Quote Link to comment Share on other sites More sharing options...
Mikula Posted December 31, 2017 Report Share Posted December 31, 2017 i do agree with your statement about the injector.. but keep in mind, just because the cylinder is misfiring intermittently, does not 100% mean its not a gasket issue. i say this because i had a cylinder that would intermittently misfire on a 98 4runner. car would shake, not accelerate, jump all over in the rpm range. then sometimes it would clear itself up, other times it would clear itself after i let it sit overnight. for whatever reason the plug would do its job some of the time, other times it was as worthless as a dead cylinder. Quote Link to comment Share on other sites More sharing options...
macbwt Posted January 1, 2018 Report Share Posted January 1, 2018 I usually say that is oil or fuel related but being only 1 cylinder is strange. any other engine i'd say the head gasket has an issue in the area of that cylinder, possibly letting coolant into the cylinder, but i don't know exactly how this motor was engineered. hell, i just learned the damn thing has an internal waterpump, so maybe someone else can step in here to help. did you pull any other plug to see if they look like this? or only the one that currently had the misfire? remind me again, is it tuned or stock? and what kind of mileage? Is this a 3.5 or a 2.7. The 2.7 has an external water pump. How hard you been running this 2.7? Any track time? This 2.7 is an open deck engine and not considered the strongest race design. 1 Quote Link to comment Share on other sites More sharing options...
commbubba19 Posted January 2, 2018 Author Report Share Posted January 2, 2018 2.7 never raced. this is a fun family car only. rarely even sees full throttle. Quote Link to comment Share on other sites More sharing options...
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