Cylinder 1 coil pack corroded. 2020 V6

Cylinder 1 misfires more when warmed up. I’m starting to think it could be a coolant leak into C1?

anyone seen anything like this before? Have a service apt. with the dealer at 8 tomorrow morning but wanted to ask around here so I can know what I might be walking into.

truck behavior shudders when warmed up especially when at lower rpms accelerating. At idle it will bounce around at 600 or so. After I pulled the coil pack it ran great for a while but then started again so I’m concerned it could be a coolant leak, which would dry out overnight/when the truck cools down, and then the coolant wouldn’t come back until the truck warms up and starts circulating. I usually only really drive it to and from work short distances from cool so it doesn’t get hot for long, and looking back I’ve had a minor shudder issue for pretty much as long as I’ve had the truck but recent hot weather brought it out stronger.

so far the only engine maintenance has been a 1k and 5k oil change (above and beyond, I know, let’s not get this thread to be about those oil changes though there’s enough of those threads).

thanks in advance!

 

Judging by what it looks like under your hood, you got muddy water in your spark plug tube somehow.

Coolant in c1? Like a blown headgasket? Not likely. I mean, anything is possible but the odds aren't that. Something got wet that shouldnt have is my bet. Been in that boat more than once with vehicles other than the taco, can't advise on that one. My money is on the coil is smoked from the mud shorting to the spark plug tube or at least sapping power and pissing off very picky electronics.

...Maybe you should clean underhood as well as possible but be prepared for the dealer to laugh you out of the shop. I'm sure someone here can give you a suggestion for readily available cleaner or some concoction to mix up and spray on then pressure wash off.

To be totally clear: I'm not shading you, in my opinion you bought an "offroad" truck and are using as such. Besides, it's your toy to use as you wish. Seriously. I wish dealers weren't like that but we know how it goes.

 

I was thinking that but the thing is it goes away when it’s dry and cool and starts misfiring when it’s warmed up again. If it is my fault that’s fine I can handle being responsible for it.

Edit to add and if it is my fault so be it but if it is an issue with a leak I want them to be the ones to inspect it and tell me that so it’s recorded. Assuming it is my fault any suggestions to remedy? Take the coil pack out when it’s warm and let it dry out + new plug and coil pack?

 

Spent coils often start acting up when hot.

I really wouldn't be worried about coolant stuff.

You said it kind of always had a skip, i wonder if you had a cracked coil case and got water in it and finished it off? Factory defects happen.

If you have a scan tool, verify the misfire location and swap the coils, clear the code, make it skip again. If the cylinder number follows the coil, well then tadaaaaa, easy-peasy fix.

 

Did you check the plug? Is it tight? Did you take it out and look at it?

 

Holy crap, you better clean it out in there before you take that plug out!

 

Agree, plug loose looks like what I'd check first. Heard of a few cases of this.

 

yup it’s cylinder 1, which is the corroded coil as well. I can swap with 5 after dealership visit. Don’t want to get too involved before they look at it. And if it was the cylinder instead of the coil I don’t want to ruin a second one in the meantime.

yeah that’s why I haven’t taken the plug out at all yet.

 

This was mine after a whole bunch of miles with a loose plug. The one on the left was the cylinder next to it with the same # of miles

 

Ah. If you were trying to see if it was just a coil and keep it off the record at the dealer, you could do the swap, that's what I was getting at.

 

Ouch... not a fun situation especially on a ‘20?

update the thread once you get it figured out I am curious. Don’t take no for an answer either... the burden of any warranty fault is usually on the dealer weather they tell you that initially or not!

 

More than likely man, it is a loose plug, or a bad seal on that plug. I doubt water got in there. I have never in my life seen water get in a properly installed coil pack on a toyota. It could happen if you submerged it, but even then they are sealed up pretty tight.

 

Hmm. Mine looks a little worse but similar, good to know thanks! I have a bicycle torque wrench which can go that low on the torque spectrum I can check that.

Oh this truck is already jacked up via dealer. At the 5k service they basically voided the frame warranty because I hammered it off road. I have another thread about that....

that I know. If it is a warranty yeah I’m not going without them fixing it. If it’s me being stupid and got water in there, that’s on me.

 

The loose plug from the factory is great info. That's the reason I hang around this forum.

Potential food for thought and I could see it being feasible and actually excusable if properly remedied: I replaced the plugs in my wife's Crosstrek, torqued them to spec with a freshly calibrated Snap-On ⅜ drive, digital torque wrench... and the damn plug came loose. Last thing I would have expected. I ended up smoke testing tracing the exhaust odor and saw a tiny wisp of smoke coming from the coil vent. WTF? Yup, that was it, carbon trail and all. It ran smooth, zero effect to drivability, power, mpg, no codes, nothing. I just kept smelling raw exhaust and it was driving me nuts! A damn loose plug. Brand new NGK OEM plug too. Craziness. No anti-sieze, all clean and dry, top quality parts and installed as precisely as a spark plug can be. Still can't wrap my head around it.

 

Ooooh, that's why your name was familiar!

Hey, where in RI did you go to beat the truck up like that? Many moons ago I conned a coworker to go wheelin after work and he ended up hydrolocking it in a retention pond somewhere off rt2 down in Exeter. Flat towed it with an XJ all the way to Balise VW on Bald Hill before we got stopped by a trooper, a west Warwick cop, an East Greenwich cop and i forgot the 4th. He opened the conversation with "What is this, a fuckin Jeep Parade?" My good friend says "well, it's more like a funeral procession, if you can see the humor in that." Trooper responds: "get that shit off of my road and call a tow." We asked "can we at least make it to Denny's, it's been a long night." "Yes but I'm following you."

The AAA driver wasn't very amused. Denny's was highly amusing, it was full of freaks from club hell in providence. Oof. This was circa 2006. I'm still great friends with funeral procession guy as are our families even a thousand miles away. Wheelin buddies can turn out to be damn good friends.

Good times.

 

Defective seals on the plugs sometimes. They crush just a little under tourqe. That tension keeps it tight and sealed. If they crush a bit more after you zip it back up, it loosens a bit every time it fires, then one day the gas finds a path, and the rest is history.

 

out at some power lines on foster. That’s awesome a funeral procession.

 

Minor update so I won’t tag people on this one. I’m an idiot. I made an appointment for Monday morning. Turns out it was next Monday. but I brought it in and left it since it was blinking they said can’t drive it (knew that). So the service advisor said they’d get it in ASAP but might not be today. Which is annoying to be sans vehicle but at least I’m not working this week and can use the wife’s car as needed intermittently. Once they diagnose and test I’ll get a call and I’ll update here.

service advisor did say that if it’s not under warranty then I’d be on the hook for diagnostics which is fine, said they’d seen similar from mice but I don’t think it’s that. But, time will tell. I even took the long route so it would be warmed up by the time I got to the dealership this morning If I’d have known I would have gone to a different dealer service since I’m not a huge fan of this one. But, I’ll reserve judgement until after.