Checking spark plug wire as we speak..
P0304 CYLINDER 4 MISFIRE IN THE EXPEDITION
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Checking spark plug wire as we speak..
Nick1994
$100 site donor 2024
Swap spark plugs with another cylinder and see if you can trade wires with that cylinder too (switching at the coil as well) and unplug the battery for a little bit to clear the code. If the code comes back check and see if the check engine light misfire code switches to another cylinder. If it does it's either the spark plug or wire. If not it might be an injector.
Originally Posted By: Nick1994
Swap spark plugs with another cylinder and see if you can trade wires with that cylinder too (switching at the coil as well) and unplug the battery for a little bit to clear the code. If the code comes back check and see if the check engine light misfire code switches to another cylinder. If it does it's either the spark plug or wire. If not it might be an injector.
I hear ya. Makes logical sense. But I cant even SEE the wires so this may need to be taken somewhere if it comes back..
Swap spark plugs with another cylinder and see if you can trade wires with that cylinder too (switching at the coil as well) and unplug the battery for a little bit to clear the code. If the code comes back check and see if the check engine light misfire code switches to another cylinder. If it does it's either the spark plug or wire. If not it might be an injector.
I hear ya. Makes logical sense. But I cant even SEE the wires so this may need to be taken somewhere if it comes back..
Is it currently running? How many miles are on it? Has it ever had a tune up? Lot of questions involved in the diagnosis here. Below is a link to a brief description of some possibilities, but more information is needed to get an accurate prognosis.
http://engine-codes.com/p0304_ford.html
Hopefully it is something simple like a faulty coil pack or spark plug. Good luck, and keep us posted!
http://engine-codes.com/p0304_ford.html
Hopefully it is something simple like a faulty coil pack or spark plug. Good luck, and keep us posted!
Usually this is a bad coil.pull that plug and go from there
Be careful with plugs in this engine. Both the 4.6 and the 5.4 have very little thread in the cylinder head that engages the plug. Stripping the threads is common if the plugs have been in there for a while. You might want to take it somewhere before touching it, unless you're good with a helicoil....
Note: I was going to say, "you should have the wheels refinished and polished first..." But this problem coming up is precisely why you can't go spending $$ on un-needed cosmetic bull$#!+...
Note: I was going to say, "you should have the wheels refinished and polished first..." But this problem coming up is precisely why you can't go spending $$ on un-needed cosmetic bull$#!+...
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OVERKILL
$100 Site Donor 2021
It's a coil. It is always a coil with a Modular. I've replaced most of mine. It does NOT have plug wires. It is coil on plug. The bolt is 8mm and you risk dropping the bolt down into the intake area, so be careful when replacing it.
OVERKILL
$100 Site Donor 2021
Originally Posted By: Nick1994
Swap spark plugs with another cylinder and see if you can trade wires with that cylinder too (switching at the coil as well) and unplug the battery for a little bit to clear the code. If the code comes back check and see if the check engine light misfire code switches to another cylinder. If it does it's either the spark plug or wire. If not it might be an injector.
That is not a realistic course of action with this engine. #4 plug (like the rest of them) is 6" down a tube, but this one in particular, being the back plug in the passenger side requires multiple extensions and a universal to get out. It has the rear heat and A/C lines running directly above it; it is the absolute worst plug in the engine and this coil goes bad due to having the coolant lines running directly over top of it and the A/C lines so it gets bathed in heat and condensation. Not one of Ford's brighter plumbing ideas.
Swap spark plugs with another cylinder and see if you can trade wires with that cylinder too (switching at the coil as well) and unplug the battery for a little bit to clear the code. If the code comes back check and see if the check engine light misfire code switches to another cylinder. If it does it's either the spark plug or wire. If not it might be an injector.
That is not a realistic course of action with this engine. #4 plug (like the rest of them) is 6" down a tube, but this one in particular, being the back plug in the passenger side requires multiple extensions and a universal to get out. It has the rear heat and A/C lines running directly above it; it is the absolute worst plug in the engine and this coil goes bad due to having the coolant lines running directly over top of it and the A/C lines so it gets bathed in heat and condensation. Not one of Ford's brighter plumbing ideas.
Originally Posted By: OVERKILL
It's a coil. It is always a coil with a Modular. I've replaced most of mine. It does NOT have plug wires. It is coil on plug. The bolt is 8mm and you risk dropping the bolt down into the intake area, so be careful when replacing it.
Not always-I had a similar problem with the E-250 4.6 2V in my sig-dealer put a coil & plug in it, no improvement-but a double dose of Techron & a tankful of Shell V-Power combined fixed it, 11 months ago.
It's a coil. It is always a coil with a Modular. I've replaced most of mine. It does NOT have plug wires. It is coil on plug. The bolt is 8mm and you risk dropping the bolt down into the intake area, so be careful when replacing it.
Not always-I had a similar problem with the E-250 4.6 2V in my sig-dealer put a coil & plug in it, no improvement-but a double dose of Techron & a tankful of Shell V-Power combined fixed it, 11 months ago.
Nick1994
$100 site donor 2024
Originally Posted By: OVERKILL
Originally Posted By: Nick1994
Swap spark plugs with another cylinder and see if you can trade wires with that cylinder too (switching at the coil as well) and unplug the battery for a little bit to clear the code. If the code comes back check and see if the check engine light misfire code switches to another cylinder. If it does it's either the spark plug or wire. If not it might be an injector.
That is not a realistic course of action with this engine. #4 plug (like the rest of them) is 6" down a tube, but this one in particular, being the back plug in the passenger side requires multiple extensions and a universal to get out. It has the rear heat and A/C lines running directly above it; it is the absolute worst plug in the engine and this coil goes bad due to having the coolant lines running directly over top of it and the A/C lines so it gets bathed in heat and condensation. Not one of Ford's brighter plumbing ideas.
Ah, I see. My grandma's Trailblazer has the coil on plugs too and it had one die. We swapped it with another cylinder and the code followed. Although these are extremely easy to get too.
Originally Posted By: Nick1994
Swap spark plugs with another cylinder and see if you can trade wires with that cylinder too (switching at the coil as well) and unplug the battery for a little bit to clear the code. If the code comes back check and see if the check engine light misfire code switches to another cylinder. If it does it's either the spark plug or wire. If not it might be an injector.
That is not a realistic course of action with this engine. #4 plug (like the rest of them) is 6" down a tube, but this one in particular, being the back plug in the passenger side requires multiple extensions and a universal to get out. It has the rear heat and A/C lines running directly above it; it is the absolute worst plug in the engine and this coil goes bad due to having the coolant lines running directly over top of it and the A/C lines so it gets bathed in heat and condensation. Not one of Ford's brighter plumbing ideas.
Ah, I see. My grandma's Trailblazer has the coil on plugs too and it had one die. We swapped it with another cylinder and the code followed. Although these are extremely easy to get too.
Hopefully it doesn't shoot out. Be careful removing that plug.
OVERKILL
$100 Site Donor 2021
Originally Posted By: bullwinkle
Originally Posted By: OVERKILL
It's a coil. It is always a coil with a Modular. I've replaced most of mine. It does NOT have plug wires. It is coil on plug. The bolt is 8mm and you risk dropping the bolt down into the intake area, so be careful when replacing it.
Not always-I had a similar problem with the E-250 4.6 2V in my sig-dealer put a coil & plug in it, no improvement-but a double dose of Techron & a tankful of Shell V-Power combined fixed it, 11 months ago.
You guys have poopy gas then, LOL! It has always been a coil for me
Originally Posted By: OVERKILL
It's a coil. It is always a coil with a Modular. I've replaced most of mine. It does NOT have plug wires. It is coil on plug. The bolt is 8mm and you risk dropping the bolt down into the intake area, so be careful when replacing it.
Not always-I had a similar problem with the E-250 4.6 2V in my sig-dealer put a coil & plug in it, no improvement-but a double dose of Techron & a tankful of Shell V-Power combined fixed it, 11 months ago.
You guys have poopy gas then, LOL! It has always been a coil for me
OVERKILL
$100 Site Donor 2021
Originally Posted By: CHARLIEBRONSON21
Hopefully it doesn't shoot out. Be careful removing that plug.
That's the only one I've had shoot out, go figure, LOL!
Hopefully it doesn't shoot out. Be careful removing that plug.
That's the only one I've had shoot out, go figure, LOL!
OVERKILL
$100 Site Donor 2021
Originally Posted By: eljefino
If that plug really is a bear maybe some slackjawed mechanic in the past replaced all 7 of the others and left this one alone.
Possible. IIRC, they are supposed to be replaced at 150,000Km (roughly 90,000 miles). I changed mine myself. Torqued them all and then six months later launched one. Also, another got loose by itself and had to be re-torqued (sounds like an exhaust leak). Been fine since (knock on wood).
That said, that coil failing is common due to what I mentioned earlier. So I would start with that. GHT does not have the tools or experience to change the plugs on this engine, I'm actually concerned about him changing the coil, particularly this one.
If that plug really is a bear maybe some slackjawed mechanic in the past replaced all 7 of the others and left this one alone.
Possible. IIRC, they are supposed to be replaced at 150,000Km (roughly 90,000 miles). I changed mine myself. Torqued them all and then six months later launched one. Also, another got loose by itself and had to be re-torqued (sounds like an exhaust leak). Been fine since (knock on wood).
That said, that coil failing is common due to what I mentioned earlier. So I would start with that. GHT does not have the tools or experience to change the plugs on this engine, I'm actually concerned about him changing the coil, particularly this one.
Originally Posted By: OVERKILL
It's a coil. It is always a coil with a Modular. I've replaced most of mine. It does NOT have plug wires. It is coil on plug. The bolt is 8mm and you risk dropping the bolt down into the intake area, so be careful when replacing it.
For some reason i thought the 97 4.6 had either COP or a wierd looking coil and plug wires?
It's a coil. It is always a coil with a Modular. I've replaced most of mine. It does NOT have plug wires. It is coil on plug. The bolt is 8mm and you risk dropping the bolt down into the intake area, so be careful when replacing it.
For some reason i thought the 97 4.6 had either COP or a wierd looking coil and plug wires?
OVERKILL
$100 Site Donor 2021
Originally Posted By: Trav
Originally Posted By: OVERKILL
It's a coil. It is always a coil with a Modular. I've replaced most of mine. It does NOT have plug wires. It is coil on plug. The bolt is 8mm and you risk dropping the bolt down into the intake area, so be careful when replacing it.
For some reason i thought the 97 4.6 had either COP or a wierd looking coil and plug wires?
I believe you are correct, the 4.6L had plug wires (likely a carry over from its use in the 'Vic) whilst the 5.4L had COP's. The OP's truck is a 5.4L, so it should be COP.
Also, I stated the wrong size earlier, it is 7mm on the COP's, not 8mm.
Not sure on what year the 4.6L went COP. Probably when they went PI.
Originally Posted By: OVERKILL
It's a coil. It is always a coil with a Modular. I've replaced most of mine. It does NOT have plug wires. It is coil on plug. The bolt is 8mm and you risk dropping the bolt down into the intake area, so be careful when replacing it.
For some reason i thought the 97 4.6 had either COP or a wierd looking coil and plug wires?
I believe you are correct, the 4.6L had plug wires (likely a carry over from its use in the 'Vic) whilst the 5.4L had COP's. The OP's truck is a 5.4L, so it should be COP.
Also, I stated the wrong size earlier, it is 7mm on the COP's, not 8mm.
Not sure on what year the 4.6L went COP. Probably when they went PI.
Check the wiring harness going to the fuel injector. An intermittent connection will cause a misfire.
Do your research on spark plug removal; don't let this engine baptize on proper plug removal technique
Do your research on spark plug removal; don't let this engine baptize on proper plug removal technique
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