po357 code on 98 expedition 5.4 misifireing skipping and knocking?

[roy13]

got the exp. 2 days ago was knocking when i got it,it doesent knock at idle..1st thing i pulled the codes which was 1st misifire on cyl.7 so i took the the coil an plug out of 7 an switched it with cyl 1 (cyl 1 had a ngk plug an cyl 7 had a motorcraft platnium..well i pulled the code again an now it says po357 something like ignition coil something? ?? but it said before 'cyl 7 misfire' ..cant get any answers anywhere so im tryin this forum..can some 1 tell me if the knocking sound is related to my misfireing on cyl 7? ive read were could be pcm but if its misfireing on cyl 7 will it make a knocking noise? any input would be greatly appreciated...thanks!

[projectSHO89]

P0357 indicates there is an electrical fault with the #7 COP. Might be as simple as a bent connector pin or a connector that isn't fully seated.

[roy13]

ok but i changed the coil pack from number 1 an switched it with number 7 coil pack an its still saying #7

[JWA]

If you switch COP's and still get the same code on cyl #7 then something in the wiring harness or perhaps the connector into the COP is at fault.

I had my own misfire on #7 and eventually discovered the locking tabs on the harness connector had failed. Replaced it with a NAPA part #EC259 and that problem was cured.

[roy13]

what bout the knocking sound is this a whole nother problem? no metal in the oil an the oil is due for oil change in 40 miles...it doesent knock at idle its more of a tapping i guess.... when im reving it at idle you can hear s,oething towards the bottom of the motor like almost like the crank turing or something? but..no metal in the oil an very good oil psi ,truck has 191k miles on it thos but motor looks almost new!

[LxMan1]

Sounds like you have a connecting rod knocking which is unrelated to the misfire.

[roy13]

ran some seafoam threw it an knocking sound quit wiring checked out fine