Burnt out ignition coils

Hey guys, first time posting.

I have a 2018 TRD Off Road with 73000km, no mods.

On Sunday my truck was running fine all day. Late afternoon I start it and it’s idling really rough, check engine is on as well as trac off light. Won’t go over 2000RPM.

Had it towed to the dealer. They called on Monday and first question was if I had power washed the engine bay, which I hadn’t. Then they asked if I had gone through a large puddle, which I hadn’t. It’s been -15 for a few weeks now, there are no puddles! And I haven’t been off road since the fall.

He said there was moisture in my ignition coils and 3 of them had burnt out. We did have a lot of snow last week and I went through some drifts on some back roads. That’s the only thing I can think of.

Anyways $800 repair. My question is has this happened to anyone else and is there a way to prevent this from happening again?

Thanks!
Newfer

 

Sucks that happened to you. Don’t think I’ve seen anyone with this issue. I’ve went through some puddles/creeks when off-road and been fine so far.

Just curious, why did you go to the dealer? I’m sure a local shop would have been cheaper.


Oh and welcome to TW!

 

I haven't had it, but winter is known to cause lots of strange and freak issues.

 

Welcome to TW

 

Thanks for the welcome! I had it taken to the dealer because I had an outstanding recall for a fuel pump replacement. Thought (hoped) that might have been the issue.

 

I pressure wash my engine fairly frequently (just did on Sunday) never an issue. Strange the coils went out

 

I avoid washing my engines at all costs now. I had minor issues both times I washed engines on my previous vehicles.

 

I see, that makes sense. Would have been nice if it was the fuel pump!

 

That's weird. The coils are sealed to the valve cover with rubber seal and a bolt. Condensation would have a hard time getting in there.

 

Would have been nice to see the codes for yourself before they tore it apart, hopefully it had coil related codes in it

I don't know what "burned out" means. Usually the insulation cracks and allows the spark to "leak" out. Burned out isn't the term i would use with a customer.

Not sure if water would cause the insulation to crack

Sometimes I wonder if they're quietly fixing the warranty issue and then padding the bill with other stuff that can (or could) cause a similar driveability symptom

 

I think the dealer was full of crap .. your part probably just failed and they blamed it on the owner . Even if u washed your engine bay it still would have be submerged in water to get in there .

 

If you’d posted from the dealer 30 seconds after service told you what the problem was, my advice would have been to have them walk you over to the truck and show you. Better yet, hand you the removed coils so you can look. And as someone else said see the codes pulled for yourself. Once the parts are replaced and the old ones go in the trash you don’t really know what happened.

Looking for yourself 1) gives you a better understanding of the potential issue with your own eyes on it, and 2) prevents you from potentially being taken for a ride.

 

Most coils have 3 wires, Toyota coils have a 4th wire that provides a feedback signal to the pcm to tell it if the magnetic field is collapsing correctly (indicator of the health of the coil). If 3 coils failed at the same time I would expect a few codes pointing at those 3 coils

 

Here’s what the repair bill states:
Codes: P0351, P0353, P0355. Checked coils, found water and dirt residue. Cleaned spark plug holes and coils 1,3 and 5. Erased codes, run engine, codes returned. Switched coils with 2, 4 and 6.
Erased codes, run engine. Codes moved to P0352,P0354 and P0356. Coils are INOE due to water damage.

 

The codes followed the coils to the other bank so that looks legit

Carry on

 

Thanks for all the info and tips! If I had known this forum was so quick and informative I would of posted here before I did anything else.

Hook, that’s great advice, I’ll be sure to follow it the next time I need repairs on a vehicle!

 

That’s true. I wonder if the visual inspection that found the moisture was before or after the swap, just out of curiosity.

 

Dang! $800! The replacement parts are only $333. That’s a heck of a lot of labor!

 

Sounds like they fuct you hard. moisture in coils sounds like total BS! Three die at the same time, No way!

 

Swapping the coils over is step 1 for most misfire diagnosis. Once they're out I'm checking them over really good for cracks and damage