5.4 2v Coil Pack
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Fleet Mechanic
Joined: Jul 2002
Posts: 1,297
Likes: 34
From: S/W Virginia
5.4 2v Coil Pack
My 03 5.4 has developed a miss under load recently. I don't know which coil it is, but I assume that it is. Spark plugs replaced probably 5K miles ago. I tow a 7k pound camper with this truck. Truck has 130K miles
I have a few questions: Should I track down which coil is bad and change just it? Or, with the miles on it, should I go ahead and change all 8?
Next question: What brand coils should I go with? Looks like Motorcraft is about $35 a piece. THere are sets of 8 all over ebay and amazon for about $25-$30. Ebay has a set of 8 MSD brand street fire for $165 or MSD Blaster for about $200.
I'm not sure which brand to go with. Any experience with any of these?
I have a few questions: Should I track down which coil is bad and change just it? Or, with the miles on it, should I go ahead and change all 8?
Next question: What brand coils should I go with? Looks like Motorcraft is about $35 a piece. THere are sets of 8 all over ebay and amazon for about $25-$30. Ebay has a set of 8 MSD brand street fire for $165 or MSD Blaster for about $200.
I'm not sure which brand to go with. Any experience with any of these?
Fleet Mechanic
Joined: Jan 2016
Posts: 1,804
Likes: 113
You should be able to scan the engine and determine which cylinder is misfiring. If you do that then swap that coil with a known good cylinder and see if the problem moves to the cylinder with the suspected bad coil If so replace that coil. FWIW, it's most likely the coil boot is bad and not the coil. Once you determine it is the coil you might swap the boot with another known good coil boot and see if the problem moves again. If so then just get a set of boots and save yourself a bunch a money.
Lead Driver
Joined: Nov 2008
Posts: 8,449
Likes: 70
From: South Jersey
My 2004 f350 with the 2valve 5.4 just hit 170k last night. I have ALL ORIGINAL COP's still...I do change the spark plugs and the boots/springs ever 30k since new. Motorcraft spark plugs with silver nerverseize and ACDelco boots (acdelco were original equipment)
Posting Guru
Joined: Jun 2009
Posts: 1,908
Likes: 20
From: Fort Smith, Arkansas
It is vastly less expensive to buy a cheapie code reader and scan the vehicle than to throw money at it parts swapping.
By far the most useful thing I have bought to work on computer controlled cars is an OBD2 adapter and Torque Pro app.
By far the most useful thing I have bought to work on computer controlled cars is an OBD2 adapter and Torque Pro app.
Fleet Mechanic
Joined: Jan 2016
Posts: 1,804
Likes: 113
FWIW, I have done a few engines with two piece spark plugs and I have never been able to get all 8 out without leaving at least 3 in the holes. I'm getting good at getting them out now. I have tried all the tricks like cracking them loose and letting penetrating oil soak for a day or so and still they break. Breaking the plugs loose is what generally causes the pieces to stay in the head. Getting the plug loose at the threads hasn't been the issue, it's the carbon buildup on the lower part of the shield sticking out in the chamber hole that causes the breakage. No amount of silver or copper coat can prevent that carbon build up and stop the breakage. The best thing is to change those plugs every 30-50k miles to avoid that carbonbuild up. If the engine is consuming oil then change them sooner to avoid that buildup.
Lead Driver
Joined: Mar 2013
Posts: 7,460
Likes: 85
From: Kent Station, WA
Most scanner's should pick up which cylinder is failing. I ran a Scanguage 2 prior to my SCT Livewire that I have now. Both pick up the codes when failed even though a Check Engine light may not illuminate.
I recommend using Denso COP's as they are the manufacturer of Motorcraft COP's. I've posted pictures showing such after another Member pointed it out.
Pick up two COP's, swap the one out and stick the other in the glovebox.
I recommend using Denso COP's as they are the manufacturer of Motorcraft COP's. I've posted pictures showing such after another Member pointed it out.
Pick up two COP's, swap the one out and stick the other in the glovebox.
Lead Driver
Joined: Nov 2008
Posts: 8,449
Likes: 70
From: South Jersey
The OP has a 2valve 5.4 so it has one piece spark plugs. Telling him he has two piece plugs and that nerverseize won't help is is just bad I formation.
OP buy a cheap scanner or have a shop pull the code for you. Swap the coil to another plug and see if that miss follows, if it does it's the cop boot OR the cop itself. If it stays then it's the spark plug OR the injector on that cylinder OR a wire issue at the plug or inside the harness
Your spark plugs should be torqued to 18ftlbs and use a light coat of silver high temp never seize on the threads.
Also use a air nozzle with an extension to blow the plug hole out, I do this before I remove the old plug and then spray brake clean down the hole and put a shop towel over it and blow it dry again (two times for each hole I'm a little OCD) then blow hole out again before I install new plug
OP buy a cheap scanner or have a shop pull the code for you. Swap the coil to another plug and see if that miss follows, if it does it's the cop boot OR the cop itself. If it stays then it's the spark plug OR the injector on that cylinder OR a wire issue at the plug or inside the harness
Your spark plugs should be torqued to 18ftlbs and use a light coat of silver high temp never seize on the threads.
Also use a air nozzle with an extension to blow the plug hole out, I do this before I remove the old plug and then spray brake clean down the hole and put a shop towel over it and blow it dry again (two times for each hole I'm a little OCD) then blow hole out again before I install new plug
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Fleet Mechanic
Joined: Feb 2011
Posts: 1,812
Likes: 88
From: Thousand Oaks, CA
FWIW, I have done a few engines with two piece spark plugs and I have never been able to get all 8 out without leaving at least 3 in the holes. I'm getting good at getting them out now. I have tried all the tricks like cracking them loose and letting penetrating oil soak for a day or so and still they break. Breaking the plugs loose is what generally causes the pieces to stay in the head. Getting the plug loose at the threads hasn't been the issue, it's the carbon buildup on the lower part of the shield sticking out in the chamber hole that causes the breakage. No amount of silver or copper coat can prevent that carbon build up and stop the breakage. The best thing is to change those plugs every 30-50k miles to avoid that carbonbuild up. If the engine is consuming oil then change them sooner to avoid that buildup.
Our 2v motors use the old style plugs.
Once you get the OEM 2 piece plugs out the replacement plugs have been upgraded to 1 piece so it shouldn't be an issue the next time around.
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Fleet Mechanic
Joined: Feb 2011
Posts: 1,812
Likes: 88
From: Thousand Oaks, CA
My 03 5.4 has developed a miss under load recently. I don't know which coil it is, but I assume that it is. Spark plugs replaced probably 5K miles ago. I tow a 7k pound camper with this truck. Truck has 130K miles
I have a few questions: Should I track down which coil is bad and change just it? ....
I have a few questions: Should I track down which coil is bad and change just it? ....
If the boots are OEM with 130k I would change all the boots, Denso 671-0001, Rock Auto, $32 for 10 boots.
Fleet Mechanic
Joined: Jan 2016
Posts: 1,804
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Edit to add: I see Champion does make a one piece spark plug but I would never put a Champion plug in a customer vehicle. In fact I won't use them in a lawnmower.
Fleet Mechanic
Joined: Jan 2016
Posts: 1,804
Likes: 113
Sometimes you can see the spark track in the boot but that is more rare than reality. Like I suggested, move the suspect coil to a different cylinder and see if the problem moves with it. If so then replace that boot. If that stops your problem then replace the rest of the boots on the other coils. If it didn't stop the problem then replace the coil. There's no sense in spending more dollars than you have to when you can make the correct diagnosis and make the proper repairs.
Posting Guru
Joined: Jun 2009
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From: Fort Smith, Arkansas