spark plug diagnosis
Thread Starter
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Senior Member
Joined: Jul 2010
Posts: 832
Likes: 2
From: NE iowa
spark plug diagnosis
02' 5.4 in f150 fx4
Just did plugs, prematurely for investigative measures.
Prior owner says that the plugs were done about 110k , now again at 158k.
compression data; cyl 1 thru 8 all had 180psi, except # 6 & #8 were down some..to 150psi...not too bad still within 15% don't perceive that is too far out of wack...maybe it is ?
( before we get too far, yes they are MC plat's AGSF 22wm that came out & MC sp479 that went in). Oh, and I replaced the PCV last week...also did that when I got the truck 2 -1/2 yrs ago, but couldn't remember that I had replaced it with MC, so I got a new one & made sure it was MC.
Now plugs #4 & #5 have pretty white accumulative deposits, aka build up on the side of the gaped prong, & center electrode is rounded. from google images it appears to be ash deposits.
All the other plugs look pretty clean but orangeish in color. Some say that the orange-ish color is from additives in the gas...others indicate that is maybe a issues with oil or coolant. The passenger side may have slightly more carbon on them vs the drivers side.
So.... is there anything overly concerning with the way the plugs look? I'm more concerned with #4  with the extra build up.
https://www.f150online.com/forums/me...ark+plugs.html
Just did plugs, prematurely for investigative measures.
Prior owner says that the plugs were done about 110k , now again at 158k.
compression data; cyl 1 thru 8 all had 180psi, except # 6 & #8 were down some..to 150psi...not too bad still within 15% don't perceive that is too far out of wack...maybe it is ?
( before we get too far, yes they are MC plat's AGSF 22wm that came out & MC sp479 that went in). Oh, and I replaced the PCV last week...also did that when I got the truck 2 -1/2 yrs ago, but couldn't remember that I had replaced it with MC, so I got a new one & made sure it was MC.
Now plugs #4 & #5 have pretty white accumulative deposits, aka build up on the side of the gaped prong, & center electrode is rounded. from google images it appears to be ash deposits.
All the other plugs look pretty clean but orangeish in color. Some say that the orange-ish color is from additives in the gas...others indicate that is maybe a issues with oil or coolant. The passenger side may have slightly more carbon on them vs the drivers side.
So.... is there anything overly concerning with the way the plugs look? I'm more concerned with #4  with the extra build up.
https://www.f150online.com/forums/me...ark+plugs.html
Senior Member
Joined: Jul 2004
Posts: 6,200
Likes: 39
From: Easton, Pa.
Aside from the observations you made, all is ok.
You can't do anything about what 4 and 5 are doing as long as it causes no issue your all ok.
Normally with fuel injection and a good overall motor the plugs will look whitesh as a normal condition.
This is because the factory speced a plug of just the right heat range to cover all conditions besides the OX sensors keeps the A/F so tight that the plugs look the way they do.
Any additives in the gas could tend to alter the surface color and the deposit build up.
The rounding of the electrodes is normal errosion from the hot combustuion gas and the sparking to ignite the mixture.
.
Believe it or not new plugs depending on what material they are made with begin to lose there 'newness' after about 600 miles let alone 100,000.
If it wasn't for the high energy of the coils and the very hard materials used in the plugs you would be replacing plugs at the old rate of 10 to 20,000 like the old motors needed for peak performance with their single coil and soft plug material..
Good luck.
You can't do anything about what 4 and 5 are doing as long as it causes no issue your all ok.
Normally with fuel injection and a good overall motor the plugs will look whitesh as a normal condition.
This is because the factory speced a plug of just the right heat range to cover all conditions besides the OX sensors keeps the A/F so tight that the plugs look the way they do.
Any additives in the gas could tend to alter the surface color and the deposit build up.
The rounding of the electrodes is normal errosion from the hot combustuion gas and the sparking to ignite the mixture.
.
Believe it or not new plugs depending on what material they are made with begin to lose there 'newness' after about 600 miles let alone 100,000.
If it wasn't for the high energy of the coils and the very hard materials used in the plugs you would be replacing plugs at the old rate of 10 to 20,000 like the old motors needed for peak performance with their single coil and soft plug material..
Good luck.
Thread Starter
|
Senior Member
Joined: Jul 2010
Posts: 832
Likes: 2
From: NE iowa
Aside from the observations you made, all is ok.
You can't do anything about what 4 and 5 are doing as long as it causes no issue your all ok.
Normally with fuel injection and a good overall motor the plugs will look whitesh as a normal condition.
This is because the factory speced a plug of just the right heat range to cover all conditions besides the OX sensors keeps the A/F so tight that the plugs look the way they do.
Any additives in the gas could tend to alter the surface color and the deposit build up.
The rounding of the electrodes is normal errosion from the hot combustuion gas and the sparking to ignite the mixture.
.
Believe it or not new plugs depending on what material they are made with begin to lose there 'newness' after about 600 miles let alone 100,000.
If it wasn't for the high energy of the coils and the very hard materials used in the plugs you would be replacing plugs at the old rate of 10 to 20,000 like the old motors needed for peak performance with their single coil and soft plug material..
Good luck.
You can't do anything about what 4 and 5 are doing as long as it causes no issue your all ok.
Normally with fuel injection and a good overall motor the plugs will look whitesh as a normal condition.
This is because the factory speced a plug of just the right heat range to cover all conditions besides the OX sensors keeps the A/F so tight that the plugs look the way they do.
Any additives in the gas could tend to alter the surface color and the deposit build up.
The rounding of the electrodes is normal errosion from the hot combustuion gas and the sparking to ignite the mixture.
.
Believe it or not new plugs depending on what material they are made with begin to lose there 'newness' after about 600 miles let alone 100,000.
If it wasn't for the high energy of the coils and the very hard materials used in the plugs you would be replacing plugs at the old rate of 10 to 20,000 like the old motors needed for peak performance with their single coil and soft plug material..
Good luck.
I thought it was a bit odd that #4 , which are about as far away from each other as cylinders can get, had mirror deposits on them.
I am pretty tickled with the compression data... I'm the 3rd owner, so I was maybe expecting worse...having #6 & #8 down a bit, does kinda raise the concern level up some. I'll see if MPGs will improve now with new plugs