Fuel injector harness/spark plug burned.. potential causes?

[GO0BER]

Hey all,

I am in my wifes 2008 Yukon xl 2500 with the 6.0; I was stuck in stop and go traffic and my wife mentioned smelling a weird smell. She then says that she can see a very faint white haze/smoke coming from under the passenger side of the hood. I quickly pull a u-turn into the open lanes of traffic and pull off the road. I had a spark plug wire (right at the coil pack) burn/get hot and then the white clip to the side of it (I believe this is part of the fuel injector harness.. I haven't had a chance to trace it yet) was damaged as well.

The spark plug wire issue caused a few check engine lights to pop on and the dreaded 'shudder' as I dropped to 7 cyl. Luckily we were only 3/4 of a mile from an oreily's that had plug wires.. Got a new wire on and it got me home with no check engine lights and running on all 8. This tells me the wires (more specifically the plug) that are burned may not be bad.. but I don't trust them.. Especially since I do not know what caused the issue in the first place.

Could a bad/failed coil arch and cause the plug wire to catch fire/melt? I assume the white plug is running low voltage/current and it shouldn't get so hot it could start a fire/ burn..

Lastly.. is it possible to get just the 'lower' (the part of the harness facing the ground) from the affected plug/pig tail or do I need to replace the whole thing? I tried doing a few searches for Fuel Injector wire harness and what I was seeing didn't match what I have pictures of. If you could help point me to potential causes and which part(s) to replace I would appreciate it.

I already have new plug wires, if I need a new coil I'll get one, the plug is my biggest 'not sure what to do' issue.

Thanks!

 

[j91z28d1]

I'm glad it didn't catch anything else on fire.

this is pretty amazing and that it ran again after you changed plug wires.

Yep, I got nothing. I believe that white plug is to the coils themselves. take it apart, a few bolts and the whole coil pack comes off the valve cover.


I'm not even going to try and guess what caused that. *edit* and it turned the silicone plug boot white.. I'm pretty sure that takes very high Temps to do

 

[Geotrash]

Wow. You’re lucky that thing didn’t burn to the ground. I can confirm that that’s the harness for the whole bank of coil packs on that side and can easily be replaced as a unit with either a junkyard part or a new one.

Here’s one on evil bay: https://www.ebay.com/itm/3253570534...mFdGJYXQey&var=&widget_ver=artemis&media=COPY

 

[iamdub]

Hey all,

I am in my wifes 2008 Yukon xl 2500 with the 6.0; I was stuck in stop and go traffic and my wife mentioned smelling a weird smell. She then says that she can see a very faint white haze/smoke coming from under the passenger side of the hood. I quickly pull a u-turn into the open lanes of traffic and pull off the road. I had a spark plug wire (right at the coil pack) burn/get hot and then the white clip to the side of it (I believe this is part of the fuel injector harness.. I haven't had a chance to trace it yet) was damaged as well.

The spark plug wire issue caused a few check engine lights to pop on and the dreaded 'shudder' as I dropped to 7 cyl. Luckily we were only 3/4 of a mile from an oreily's that had plug wires.. Got a new wire on and it got me home with no check engine lights and running on all 8. This tells me the wires (more specifically the plug) that are burned may not be bad.. but I don't trust them.. Especially since I do not know what caused the issue in the first place.

Could a bad/failed coil arch and cause the plug wire to catch fire/melt? I assume the white plug is running low voltage/current and it shouldn't get so hot it could start a fire/ burn..

Lastly.. is it possible to get just the 'lower' (the part of the harness facing the ground) from the affected plug/pig tail or do I need to replace the whole thing? I tried doing a few searches for Fuel Injector wire harness and what I was seeing didn't match what I have pictures of. If you could help point me to potential causes and which part(s) to replace I would appreciate it.

I already have new plug wires, if I need a new coil I'll get one, the plug is my biggest 'not sure what to do' issue.

Thanks!

Judging by the white soot, I'm gonna guess you had a high voltage leak and arcing to the low voltage harness nearby. Just my guess. But, apparently, a freak incident nonetheless.

That harness with the large white connector is for the ignition coils, not the fuel injectors. Look at the driver side (both sides are identical/interchangeable) to get a better idea. You can buy just the harness for them ignition coil plugs. Quick search shows it should be under $100. It looks like you can clean up the upper half of that harness connector by picking off the molten plastic of the lower half. Or, and this is what I'd do, is buy a whole rack of coils with the harness in place from a salvage yard or from someone parting out an LS engine. I see this sort of stuff ALL the time on Marketplace. You should be able to get the whole shebang for less than just that harness and you wouldn't have to bother with R/R that harness. The whole rack comes off with just five 10mm bolts and that one harness connector in the center. You'd also have some spare ignition coils. Actually, here's an example on ebay of both racks, coils and harnesses for $100. Or, get both sides with the better factory coils (round) and make lemonade of this by upgrading. Here's some for about $85 on ebay. Those are just quick searches and you could probably find everything for much cheaper. *EDIT* I see Dave @Geotrash found you a quick fix for $35! Also, after studying your pic more, you might already have the round coils. They looked square at first.


What a rack of coils looks like:




These are the upgraded coils:

 

[Dustin Jackson]

I would recommend getting a fire extinguisher moving forward.

 

[GO0BER]

Thanks all for the help. Not sure why I didn't think of coil harness instead of injectors.. It was a frustrating evening to say the least.

Is there any inherent risk with buying used coils? I did a quick search and found summit sells all 8 for about $300.. Without the harness.. I don't mind used parts but after seeing several of you mention how lucky I am this wasn't worse I would happily pay the extra money if there is benefit.

If no benefit I'll be ordering off eBay in the morning.

 

[Doubeleive]

Thanks all for the help. Not sure why I didn't think of coil harness instead of injectors.. It was a frustrating evening to say the least.

Is there any inherent risk with buying used coils? I did a quick search and found summit sells all 8 for about $300.. Without the harness.. I don't mind used parts but after seeing several of you mention how lucky I am this wasn't worse I would happily pay the extra money if there is benefit.

If no benefit I'll be ordering off eBay in the morning.

looks like you had a short to ground and a ground will always take the shortest path which happened to be the valve cover or head.
you should have been smelling something.......
no risk in buying and using used coils or harness but check the ground!, make sure it ohm's to zero

you might want to check those 2 closest coil packs as well look on the backside it's possible one of them developed a crack and everything went haywire.
I bet that was a light show at night under the hood

 

[Geotrash]

Thanks all for the help. Not sure why I didn't think of coil harness instead of injectors.. It was a frustrating evening to say the least.

Is there any inherent risk with buying used coils? I did a quick search and found summit sells all 8 for about $300.. Without the harness.. I don't mind used parts but after seeing several of you mention how lucky I am this wasn't worse I would happily pay the extra money if there is benefit.

If no benefit I'll be ordering off eBay in the morning.

I looked and didn't see the harness on RockAuto and that's the part that's burned so you'll at least need that from evil bay. Might as well replace all of those coils with new, along with new plugs and wires while you're in there.

 

[j91z28d1]

you might check the coil fuse has the correct size in it. I don't know if you're the original owner, but maybe someone stuck a 30amp where a 15 should go, or whatever is supposed to be in there. the lid should say what should be in it

freak accident forsure.. I'd just buy a used bank off ebay, hopefully the upper part of the plug is still in OK shape. maybe replace the spark plug just for the heck of it. I don't think a plug can cause that, but who knows forsure at this point.

 

[donjetman]

I'd be shopping the wreaking yards or ebay for the parts you want.