Plugs Corroding
Thread Starter
Member
Joined: Mar 2025
Posts: 48
Likes: 9
yes, it shocked me too! It was running and just barely noticeably rough, with a check engine light on and only showing cylinder seven as problematic
5 Year Member
Joined: Feb 2020
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PLUGS:
were any other changes made at same time as plug change?
what did the previous set look like when they were pulled (6k miles ago)?
if they looked fine, and if you didn’t install the previous set, then i would put in fresh plugs using proper technique / torque. resume driving and then pull one of troubled cyls in about 3k and inspect. next steps based on results.
COOLANT:
wondering you have two issues, and this coolant could be separate from plugs
had you been watching your coolant prior to last 6k miles?
when did the loss start?
i don’t see engine model noted, but on 4.6 the intake manifolds are notorious for leaking at crossover… which is closed to 1,5, 2, 6. coolant will pool into plug wells and typically cause misfires. but if you didnt torque properly, i guess it’s possible that it would deep down in??
suggest taking a close reading of level when stone cold, then monitoring changes (also at stone cold. you can also pull up 1 and 2 coil boots periodically and check for coolant
EDIT/PS: if you didn’t change out boots/springs last time, definitely do that while changing this time.
were any other changes made at same time as plug change?
what did the previous set look like when they were pulled (6k miles ago)?
if they looked fine, and if you didn’t install the previous set, then i would put in fresh plugs using proper technique / torque. resume driving and then pull one of troubled cyls in about 3k and inspect. next steps based on results.
COOLANT:
wondering you have two issues, and this coolant could be separate from plugs
had you been watching your coolant prior to last 6k miles?
when did the loss start?
i don’t see engine model noted, but on 4.6 the intake manifolds are notorious for leaking at crossover… which is closed to 1,5, 2, 6. coolant will pool into plug wells and typically cause misfires. but if you didnt torque properly, i guess it’s possible that it would deep down in??
suggest taking a close reading of level when stone cold, then monitoring changes (also at stone cold. you can also pull up 1 and 2 coil boots periodically and check for coolant
EDIT/PS: if you didn’t change out boots/springs last time, definitely do that while changing this time.
Thread Starter
Member
Joined: Mar 2025
Posts: 48
Likes: 9
PLUGS:
were any other changes made at same time as plug change?
what did the previous set look like when they were pulled (6k miles ago)?
if they looked fine, and if you didn’t install the previous set, then i would put in fresh plugs using proper technique / torque. resume driving and then pull one of troubled cyls in about 3k and inspect. next steps based on results.
COOLANT:
wondering you have two issues, and this coolant could be separate from plugs
had you been watching your coolant prior to last 6k miles?
when did the loss start?
i don’t see engine model noted, but on 4.6 the intake manifolds are notorious for leaking at crossover… which is closed to 1,5, 2, 6. coolant will pool into plug wells and typically cause misfires. but if you didnt torque properly, i guess it’s possible that it would deep down in??
suggest taking a close reading of level when stone cold, then monitoring changes (also at stone cold. you can also pull up 1 and 2 coil boots periodically and check for coolant
EDIT/PS: if you didn’t change out boots/springs last time, definitely do that while changing this time.
were any other changes made at same time as plug change?
what did the previous set look like when they were pulled (6k miles ago)?
if they looked fine, and if you didn’t install the previous set, then i would put in fresh plugs using proper technique / torque. resume driving and then pull one of troubled cyls in about 3k and inspect. next steps based on results.
COOLANT:
wondering you have two issues, and this coolant could be separate from plugs
had you been watching your coolant prior to last 6k miles?
when did the loss start?
i don’t see engine model noted, but on 4.6 the intake manifolds are notorious for leaking at crossover… which is closed to 1,5, 2, 6. coolant will pool into plug wells and typically cause misfires. but if you didnt torque properly, i guess it’s possible that it would deep down in??
suggest taking a close reading of level when stone cold, then monitoring changes (also at stone cold. you can also pull up 1 and 2 coil boots periodically and check for coolant
EDIT/PS: if you didn’t change out boots/springs last time, definitely do that while changing this time.
Sometime after the plug change, I did a reverse flush on my heater core, but I really don’t think I got any water on the engine or the spark plugs.
I’ve taken your advice and use a torque wrench to reinstall the plugs. I will finish tomorrow.
Coolant: this is something I am going to have to watch and see if I can determine where it is disappearing to ever so slowly. But I will use your technique.
I will recheck them in about three months to see how things are looking. Thanks guys. I appreciate it.
5 Year Member
Joined: Feb 2020
Posts: 7,714
Likes: 2,196
Plugs: I replaced them all at the same time and did no other changes at that time. The old plugs looked old and mildly dirty, but nothing surprising.
Sometime after the plug change, I did a reverse flush on my heater core, but I really don’t think I got any water on the engine or the spark plugs.
I’ve taken your advice and use a torque wrench to reinstall the plugs. I will finish tomorrow.
Coolant: this is something I am going to have to watch and see if I can determine where it is disappearing to ever so slowly. But I will use your technique.
I will recheck them in about three months to see how things are looking. Thanks guys. I appreciate it.
Sometime after the plug change, I did a reverse flush on my heater core, but I really don’t think I got any water on the engine or the spark plugs.
I’ve taken your advice and use a torque wrench to reinstall the plugs. I will finish tomorrow.
Coolant: this is something I am going to have to watch and see if I can determine where it is disappearing to ever so slowly. But I will use your technique.
I will recheck them in about three months to see how things are looking. Thanks guys. I appreciate it.
Senior Member
Joined: Sep 2023
Posts: 855
Likes: 483
Never saw coolant erode spark plugs. Water or coolant in the cylinder creates steam which will clean carbon from the plugs and piston. Not sure what you have going on there but its not being caused by coolant in the cylinder.
Some additives and fuel treatments cause rusty looking deposits. I dont think an extreme overdosing of those could erode steel like that but it could be possible. Do you use any specific fuel treatments or other fuel tank snake oil?
Ditch those E3's and get a name brand single electrode plug, Motorcraft or NGK, and start over.
Some additives and fuel treatments cause rusty looking deposits. I dont think an extreme overdosing of those could erode steel like that but it could be possible. Do you use any specific fuel treatments or other fuel tank snake oil?
Ditch those E3's and get a name brand single electrode plug, Motorcraft or NGK, and start over.
5 Year Member
Joined: Dec 2018
Posts: 4,442
Likes: 1,190
From: Ocean Springs MS
Bruce,
I realize this question may be a little late, assuming you have already replaced the plugs.
How did the threads in the head (for the spark plugs) look?
Did the installation go as planned?
Were you able to torque properly?
Additional Comment copied from web
Erosion of the Mounting Area (Threads & Hole)
I realize this question may be a little late, assuming you have already replaced the plugs.
How did the threads in the head (for the spark plugs) look?
Did the installation go as planned?
Were you able to torque properly?
Additional Comment copied from web
Erosion of the Mounting Area (Threads & Hole)
- Loose Installation: If a spark plug is not tightened to the correct torque, it can vibrate. This vibration, combined with hot combustion gases leaking past the loose threads, causes severe erosion of the aluminum threads in the cylinder head.
- Blow-by and Compression Leaks: When gases escape through the spark plug hole (often due to a failed seal or damaged threads), the high-pressure "torch-like" effect of the escaping gas can erode the surrounding metal of the engine head.
Thread Starter
Member
Joined: Mar 2025
Posts: 48
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They are all in and I was able to torque them properly. As the time I was not looking for the condition of the threads in the head so I do not know. But all of the plugs torque down as desired. The first test run that night the car started and ran smoothly. When I drove it the next day it is running rough again! I drove it about 35 miles to see if I could get a code, but I think it takes 50 for a code to show up. The saga continues.
5 Year Member
Joined: Dec 2018
Posts: 4,442
Likes: 1,190
From: Ocean Springs MS
Assuming that you currently have a misfire then there should be "pending" codes stored that can be read with a code reader. Autozone and others will read these codes for free. Buy nothing, report back.
5 Year Member
Joined: Dec 2018
Posts: 4,442
Likes: 1,190
From: Ocean Springs MS
You should take a look at this video.
I guess its possible that the reason the truck is not running well may now be damaged coils (COPs) and/or heat affected coils due to exhaust gases leaking by (still) the threads and overheating the coils. Video shows this for that particular engine.
Your problem looks like a disaster, hope I am wrong.
Myself and others, based on our past experience, will continue of offer advice, best we can.
I guess its possible that the reason the truck is not running well may now be damaged coils (COPs) and/or heat affected coils due to exhaust gases leaking by (still) the threads and overheating the coils. Video shows this for that particular engine.
Your problem looks like a disaster, hope I am wrong.
Myself and others, based on our past experience, will continue of offer advice, best we can.