Hesitation / Miss under load
11-21-2016, 03:51 PM
#1
Hesitation / Miss under load
Hey guys, my 2006 f150 5.4 is hesitating / missing under load in overdrive around 40 to 55 mph. I replaced the spark plugs at 100,000 miles with auto light spark plugs and fixed this problem the first time. The coil packs are original, truck currently has 140,000 miles on it. Now the hesitation is back do I need plugs and coils? Or one or the other Thanks.
11-21-2016, 05:48 PM
#2
At 140K it doesn't seem unreasonable that your coils would go bad. My 07 4.6 did the same thing right around 95K and I did plugs and coil packs/boots and fixed the issue, going strong now at 115K. Seems to me like I'd just do them all (plugs and coil packs/boots) and be done with it since plugs aren't the expensive part of that operation (assuming you're doing the labor yourself). It'll just be more hassle if you do the coils only and don't fix the issue
Last edited by V1Rotate; 11-21-2016 at 06:16 PM.
11-21-2016, 07:00 PM
#3
At 140K it doesn't seem unreasonable that your coils would go bad. My 07 4.6 did the same thing right around 95K and I did plugs and coil packs/boots and fixed the issue, going strong now at 115K. Seems to me like I'd just do them all (plugs and coil packs/boots) and be done with it since plugs aren't the expensive part of that operation (assuming you're doing the labor yourself). It'll just be more hassle if you do the coils only and don't fix the issue
11-21-2016, 08:30 PM
#5
Senior Member
Often when you have a coil going bad it takes out the plug. People then pull the plugs, see an issue and assume they have fixed the problem when they really just fixed the symptom.
11-22-2016, 07:28 AM
#7
Mark
iTrader: (1)
The only good thing about having Autolites in there is they will come out without breaking. Replace your plugs with a fresh set of motorcraft SP 515's and new boots and springs.. go from there.
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11-22-2016, 10:20 AM
#8
05 5.4l 3v s.crew lariat
Change your plugs and boots -clean out carbon .
Use dialectic grease on boots properly. There are posts on here about cleaning out spark plug holes of the burnt carbon around the tips . Carefully air blow out holes before you start and or vacuum them out . Use carb cleaner on holes but make sure you let the liquid clear out before putting sparkplug in ,you don't want to hydro lock it .
F150torqued has an interesting post about carbon build up damaging new plugs etc. .
Torque your sparkplugs in and change them before 60k .
I have lost f150T link to cleaning out hole or I would send it .
I change plugs around 30k and I use nickle antiseize on tips per ford TSB .
F150torqued has an interesting post about carbon build up damaging new plugs etc. .
Torque your sparkplugs in and change them before 60k .
I have lost f150T link to cleaning out hole or I would send it .
I change plugs around 30k and I use nickle antiseize on tips per ford TSB .
11-22-2016, 10:34 AM
#9
TOTM 8/2019
I have the same issue. Changed the plugs at 105k, ran great, and starts to miss again and I'm at around 130k. I didn't do plugs/boots when I did the plugs, so I will do that soon.