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Hello, My 04 FX4 starting missing last weekend with no codes, so I figured it was time to do the plugs and coils. When removing the plugs I found cyl 5, 6 and 7 were both discolored brown and the boots had also discolored brown. Boots also have a oil/gas smell to them. Not really sure what would cause this or what exactly it is. I don't see any oil leaks around the valve covers. 6 and 7 are shown in the pictures, 5 was not as bad. 8 was clean. 1 - 4 also came out perfect.
To top things off one coil screw is stripped so the coil won't tighten back down, and two clips on the coil harness broke. Any issues driving it before fixing those harnesses? And can I leave the coil loose where the screw won't tighten?
Hello, My 04 FX4 starting missing last weekend with no codes, so I figured it was time to do the plugs and coils. When removing the plugs I found cyl 5, 6 and 7 were both discolored brown and the boots had also discolored brown. Boots also have a oil/gas smell to them. Not really sure what would cause this or what exactly it is. I don't see any oil leaks around the valve covers. 6 and 7 are shown in the pictures, 5 was not as bad. 8 was clean. 1 - 4 also came out perfect.
To top things off one coil screw is stripped so the coil won't tighten back down, and two clips on the coil harness broke. Any issues driving it before fixing those harnesses? And can I leave the coil loose where the screw won't tighten?
Thanks in advance!
The harnesses might wiggle off after a while. Maybe a small zip tie until you can get new connectors.
You have blowby - plugs loose . It will destroy plugs and boots . The oxygen sucked in on intake stroke helps fuel the hot carbon around the plug tip and the pressure out on compression blows hot gases up the plug burning the boot . It acts just like a cutting torch . Torque plugs in 25 to 28 foot pounds with a torque wrench . Change plugs and all boots . That carbon is very tough and glows white hot. Use carb cleaner to melt carbon when doing plugs . Fuel additives can't even try to get into that recess around plugs . That carbon breaks plugs going in and out .
You have blowby - plugs loose . It will destroy plugs and boots . The oxygen sucked in on intake stroke helps fuel the hot carbon around the plug tip and the pressure out on compression blows hot gases up the plug burning the boot . It acts just like a cutting torch . Torque plugs in 25 to 28 foot pounds with a torque wrench . Change plugs and all boots . That carbon is very tough and glows white hot. Use carb cleaner to melt carbon when doing plugs . Fuel additives can't even try to get into that recess around plugs . That carbon breaks plugs going in and out .
Thanks that is what I thought was happening, but was looking for confirmation.
I had the torque wrench on those plugs, but it seemed like they just kept going, I didn't want to break one or damage the head. Not sure if I should keep going on them or not. Definitely more turns going on those then the other plugs took to get to 25 ft/lb
Also explains the sounds getting those out, lots of screeching. Whoever did them last didn't use anti-seize on the lower part of the plug or dielectric grease on the boots.
Spark Plug Color
