View Full Version : bad coil packs?

12-15-2013, 03:18 PM
Not a SC problem, but the 2.5 duratec in my 98 contour shares the same coil packs as the SC. Got a blinking check engine lite, misfire bad enough to damage converters. Misfire on cyls 1,2,and 3. Replaced the coil pack with one from federated. Ran great for 10-12 days-2 wks. Now the same misfire 1,2,and 3 is back. Dbl plat motorcraft plugs and wires, ford o2 sensors, and full tune up was done in Mar '12, so plugs and wires r less than 15k. Inspected wires, they r good, pulled plugs and they looked fine too. This is a waste spark motor, just like SC's, what could cause one bank only coilpack failure? I thought maybe it was an injector problem, not ignition, but why would changing the pack clear the problem for 2 wks if it was injectors, or harness? Did a full wiggle test had could not get any change. Not showing any other codes, and watching sensors on the scanner, all seem to be functioning and correct (TPS, IAT, ECT, load, Massair%, timing, ect r in the expected ranges and changing as the car warms up, if reved ect).

HELP!!! I don't want to just keep throwing coil packs in and burning them up!
I need this car to be reliable (at least one of my rides has 2 B :cool:)

Thanks 4 suggestions or ideas


12-15-2013, 03:24 PM
Those motors are known for causing misfires due to bad intake gaskets. FYI, if the coil goes bad, it will misfire on the 2 paired cylinders, so the fact that 1, 2, and 3 were misfiring tells me that it definitely was not a bad coil pack. Replace the intake gaskets, and I'll bet the problem will go away. Also, the lean condition that the bad intake gaskets cause would explain the melted down cat as well.

12-15-2013, 07:48 PM
Yeah Mike, Thanks. I was coming to the same conclusion, couldn't make sense of the 3 coils failing on one and not the other paired cyl. Don't think it's melted the cat YET :cool: , but flashing check engine light indicates a problem bad enough TO damage the cat, hope I caught it soon enough, had the rear cat replaced once, the shop that did it said it was the worst cat R&R they had ever seen, and would never do another! This car has had a minor oil seep/leak for quite a while that I could never trace bcause it dripped on the pullies/belt and got flung all over, and on a deeper inspection it seems to have gotten worse as well. That deff points to the intake. Didn't know these had a known problem with that. Live and learn.:rolleyes: Just wonder why I seem to always learn these things in 4-6 inches of new snow :rolleyes:


12-15-2013, 07:54 PM
OH yeah, I figured it wasn't the coil when I pulled the wire ands had an inch long spark jump the gap, and you could hear it drop that cylinder! And as a side note, the coils LOOK the same, but r wired opposite. When I swapped in the SC coil I had on the shelf, the code changed to 4,5,and6 cyl, but the operation of the car didn't change.