Car Problem Reports

Ford F-150 Ignition Coil Failure Due to Excessive Spark Plug Gap

Ford F-150 Problem
58 Reports
Me Too

Model Years Affected: 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2009

Engines Affected: 4.2L V6, 4.6L V8, 5.4L V8, 6 Cylinder, V8

Average Mileage: 111,332 mi (22,000 mi - 200,000 mi)


An illuminated Check Engine Light could indicate that one or more of the ignition coils has failed due to excessive spark plug gap. To fix this problem, the ignition coils that have failed, the spark plugs, and all coil boots should be replaced.

  • Visitor, , 5.4L V8, 136,000 mi

    i was driving and i herd a pop like something hit my hood and then the truck sounded like a motorcycle, i took it to a friend and he said the # 4 plug popped out. so he fixed it for me but a year later i still have problems with misfire on #4 had new boots put in but every six months still misfires

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  •  Rookie

    What is happening with these coils going is a few things. First the spark plug could be bad causing the coil to go and secondly the plug wire ends if they do not have di-electric grease packed in both ends, the least bit of moisture is enough to screw it up. These models have been known to have a bad design as far as the coils (in which #5 and #7 are ususally the culprits ) of letting water in the wells where the plug is. I am experiencing it also but have found a guy that knows exactly how to fix the problem. My conversation had just started and he stopped me and said, " Let me guess, this is whats happening " and he was spot on and continued to tell me how he has fixed them.... two weeks before he can get to it though....grrrrrr.

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  • HarryW, , 5.4L V8, 60,000 mi

    If the spark gap is set to Ford's spec.s, what the h... is the gap that will keep the d... coils from blowing. I have experienced failures about every 3 to 6 months for the last couple of years. Going send me right back to Jap trucks.

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  • Visitor, , 5.4L V8, 96,000 mi

    misses when i go to accelerate

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  • CandG, , 5.4L V8, 80,000 mi

    A couple years ago I was driving home and all the sudden engine light came on and car started sputtering/ misfiring around 50 miles per hour. Had full tune up done which cost a lot of money, replaced all spark plugs and coils. Since then every few months same issue with 1 coil = #5. Replace spark plug and coil/boot assembly and good for another couple months, pain in the butt. UNHAPPY Truck has been taken care of ... only has 115,000 miles and should not have to deal with this every few months :(

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  • Visitor, , 5.4L V8, 128,000 mi

    engine was missing between 40-50 mph until the check engine light was continuosly lit no codes were revealed. mine was the number 1 cylinder i replaced just the one as 1,000 for all 8 is out of my budget.

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  • Visitor, , 4.6L V8, 157,768 mi

    Vehicle started skipping intermittently, expecially noticable when I accellerated. I replaced the ignition coil.

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  • Visitor, , 4.6L V8, 145,000 mi

    Engine cut out during light acceleration. More often on warm weather

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  • Big Red Dog, , 4.6L V8, 158,000 mi

    Bought used truck with 100K on meter; at about 120K, the engine began eating coils about 1 each year for the last couple of years. First was #4 in the summer, then #6 the following spring, now, #5 in the mid of winter. "Check Engine Light" didn't come on until the miss was very bad.

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  • Visitor, , 5.4L V8, 119,062 mi

    Engine light came on ran test with scanner found a miss fire code. Found bad coil removed spark plugs all where bad along with one coil. 2 of the spark plugs where stuck in the head and had to be removed coasting extra money. now it runs great.

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