7.3L spark plug/coil wire failure

[Raspy]

Mine looked like they burned from the inside. Seems to me more like a result of electrical arching inside the insulation so not sure adding the fiberglass plug boots would do anything.

This is what I found too. Everybody has been talking about failure from heat, but my carbon string conductor was burned out along the interior of the insulation, from elecrical arcing. That makes a gap in the conductor that gets longer and longer until the spark can't jump it.

For those interested, look at my earlier post on this where I cut the wire open to show it was burned inside.

 

[Raspy]

For those of you who have purchased the "D" version, have you put them on yet and if so, are they working OK? Getting ready to go on a long road trip and want to buy some spare wires but can't find the "C" versions.

I got my "C" wires at Rockauto and they were cheap.

 

[Donnie With A Dee]

Motorcraft Spark plugs: SP-589. Gap is .049-.053

I'm trying to order plugs right now and Rock Auto says it is DP-586 not 589. Can you confirm? Thanks

 

[Donnie With A Dee]

I got my "C" wires at Rockauto and they were cheap.

Thanks for the reply, but Rock Auto doesn't offer them anymore. It specifies the "D" type now. Doesn't offer the "C". That is why I was asking.
Still haven't heard if anyone has actually installed them yet.

 

[Raspy]

Thanks for the reply, but Rock Auto doesn't offer them anymore. It specifies the "D" type now. Doesn't off the "C". That is why I was asking.
Still haven't heard if anyone has actually installed them yet.

I'm not promoting the "C" wires. Just reporting my experience. If you can get "D" wires, get them. Maybe Ford will eventually figure this out. Sheesh.

 

[Donnie With A Dee]

I'm not promoting the "C" wires. Just reporting my experience. If you can get "D" wires, get them. Maybe Ford will eventually figure this out. Sheesh.

Based on the positive feedback of the "C" on this forum, those are the type I wanted.

 

[Explorerinil]

I ordered a set of wires from rock auto yesterday. They should be here today. I’ll post a pic of what they send me, it looks like the D version from the description.

 

[Modman]

I'm trying to order plugs right now and Rock Auto says it is DP-586 not 589. Can you confirm? Thanks

From the 2022 Owners Manual:

 

[Donnie With A Dee]

From the 2022 Owners Manual:

View attachment 129387

Ok. Thanks. Mines a 21' so maybe that's the difference. I'll have to get the book out.

 

[Raspy]

Ok. Thanks. Mines a 21' so maybe that's the difference. I'll have to get the book out.

Mine is a 21 too. Does anyone know the torque spec on the spark plugs? BTW, what is the change interval? I'm at about 78,000 miles now. I've got a set of 589 plugs sitting here waiting to go. Thanks.

 

[Modman]

Mine is a 21 too. Does anyone know the torque spec on the spark plugs? BTW, what is the change interval? I'm at about 78,000 miles now. I've got a set of 589 plugs sitting here waiting to go. Thanks.

Torque is 15Nm +/- 5. (11lbft +/-3.7)

100k is the normal service interval
60k is the severe service interval with this qualification:

"If you operate your vehicle primarily in any
of the following conditions, you need to
perform extra maintenance as indicated.
If you operate your vehicle occasionally
under any of these conditions, it is not
necessary to perform the extra
maintenance.

Towing a Trailer or Using a Car-top Carrier"

 

[Donnie With A Dee]

Mine is a 21 too. Does anyone know the torque spec on the spark plugs? BTW, what is the change interval? I'm at about 78,000 miles now. I've got a set of 589 plugs sitting here waiting to go. Thanks.

Just received my spark plugs from Rock Auto and they are SP-586's not 589's. I found the owners manual and for the 21's, it calls for the SP-586. I don't know if there's much difference but your truck is also a 21'.

 

[Raspy]

Just received my spark plugs from Rock Auto and they are SP-586's not 589's. I found the owners manual and for the 21's, it calls for the SP-586. I don't know if there's much difference but your truck is also a 21'.View attachment 129707

Thanks Donnie.

 

[MrFancypants]

Just a thought - how many people that have burnt out wires are using the factory Motorcrap battery? Wondering if a low voltage condition makes for excess current and, well, melting.

 

[Raspy]

Just a thought - how many people that have burnt out wires are using the factory Motorcrap battery? Wondering if a low voltage condition makes for excess current and, well, melting.

The alternator and its controller are what determine system voltage when the engine is running. It is normally about 14 -14.5 volts

 

[MrFancypants]

The alternator and its controller are what determine system voltage when the engine is running. It is normally about 14 -14.5 volts

I was thinking more during starting conditions when current from the battery is the highest and the voltage may drop. Not sure how the coil packs work through.

 

[Fat1matt]

I have a 7.3L 2022 Tremor 66K miles and received a misfire on cylinder 1 passenger front cylinder. I pulled the wire to have a look and after plugging it back in and clearing the code it hasn't come back? Was the wire loose causing the problem? I just pulled it off and didn't notice.
I ordered from Ford.com the full replacement kit with all eight wires and coils. Is the recommendation to replace them all since I am at 66,000 miles and pull a 9K airstream for travel? Suggestions please.

 

[Maverick11]

Wires- yes. I can’t speak to the rest of that kit… wires are a known issue. I have a 2021 and had the same issue before 50k. I replaced all 8 with the upgraded version at the time and now at 108k with no repeat of the issue. Will probably replace wires soon when I do spark plugs.

 

[Modman]

I pulled the wire to have a look and after plugging it back in and clearing the code it hasn't come back?

That was one issue (there were several others) with the original plug wires. They did not have a positive, resilient connection. Unfortunately, I would guess that problem will show itself again. I would upgrade to the latest service wires.

 

[Fat1matt]

That was one issue (there were several others) with the original plug wires. They did not have a positive, resilient connection. Unfortunately, I would guess that problem will show itself again. I would upgrade to the latest service wires.

They did not have a positive, resilient connection. Sorry do you know if the new kit I ordered has been corrected or am I just replacing with the same stuff as shipped with? Thanks for the feedback