Bad Coils?
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Just FYI, the pre-2000 4.6 did not use the coil-on-plug design found on all 5.4's and 2000+ 4.6. Instead, it has just two coils, each located at the front of the cylinder bank. In this design, it's less likely that leaking coolant is causing a misfire problem on #4 cylinder, unless the leak is heavy enough to fill the spark plug well.
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Joined: Dec 2003
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Hello Graig ,
# 4 is on the passenger side , all the way in the back . Its a bitch to get to , but if your patient you can get it . A few notes on this problem , depending on the miles on your truck , you may want to do a tune up . That means plugs and if over 50000 , I would replace the spark plug boots , there availible at napa , it gets really hot in there and the ones I have seen get all cracked and dry rotted . Make sure you use motorcraft platinums spark plugs and get some dielectic grease and lube up the boot on the end before you install them . The boots are just like spark plug wires , they get old . As far as your #4 spark coil , make sure your heater
hose is not leaking and make sure your fire wall is not leaking from the outside . Run a garden hose on the windsheild and let it run down and watch for leaks . I have had # 4 go bad on mine , it actually cracked right on top , you could feel it when you run your finger across the top , it should be smooth and mine acted up when I washed it due to the firewall leak . Also , be careful when you thread the plugs in , do not cross thread them as they will blow out eventually and ruin the head , make sure they thread by hand easily before you wrench them in . If you have any other questions , just email me . Hope this helps ya !!
# 4 is on the passenger side , all the way in the back . Its a bitch to get to , but if your patient you can get it . A few notes on this problem , depending on the miles on your truck , you may want to do a tune up . That means plugs and if over 50000 , I would replace the spark plug boots , there availible at napa , it gets really hot in there and the ones I have seen get all cracked and dry rotted . Make sure you use motorcraft platinums spark plugs and get some dielectic grease and lube up the boot on the end before you install them . The boots are just like spark plug wires , they get old . As far as your #4 spark coil , make sure your heater
hose is not leaking and make sure your fire wall is not leaking from the outside . Run a garden hose on the windsheild and let it run down and watch for leaks . I have had # 4 go bad on mine , it actually cracked right on top , you could feel it when you run your finger across the top , it should be smooth and mine acted up when I washed it due to the firewall leak . Also , be careful when you thread the plugs in , do not cross thread them as they will blow out eventually and ruin the head , make sure they thread by hand easily before you wrench them in . If you have any other questions , just email me . Hope this helps ya !!
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Joined: Feb 2004
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Blu97xlt
I'm having the same problems with my truck (hesitation to accelerate at 40-50mph) so I brought it to a dealer this morning. How long ago did you have it serviced and did it completely solve the problem? Did you also replace the spark plug boots?
I'm having the same problems with my truck (hesitation to accelerate at 40-50mph) so I brought it to a dealer this morning. How long ago did you have it serviced and did it completely solve the problem? Did you also replace the spark plug boots?
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