How to test COPs (coil on plugs), '01 F150 w/155K miles misfire??
#1
How to test COPs (coil on plugs), '01 F150 w/155K miles misfire??
Waiting for AAA as I write this
Started truck up at lunch, noticed a slight "hiccup", turned off truck, started it back up, idled fine. A few hours later left to drive home, ran fine for 10 minutes, now it's worse.
Shake is worse with load, from what I've been reading it sounds like the COPs give up at about this time frame/mileage???
Any way to test them with a voltmeter or scope?
thanks
Started truck up at lunch, noticed a slight "hiccup", turned off truck, started it back up, idled fine. A few hours later left to drive home, ran fine for 10 minutes, now it's worse.
Shake is worse with load, from what I've been reading it sounds like the COPs give up at about this time frame/mileage???
Any way to test them with a voltmeter or scope?
thanks
#2
Mueller, I was always able to find the bad one by comparing readings on an ohm meter. I don't know what value I got but, I replaced the one with a value that was way off compared to the others. For me it was easier to remove them and test them on a bech. It fixed it for me. Autozone now stocks them, if you shop aroung you can get a good deal. If I remember I had Autozone match checkers price of $35-40.
Good luck!
Scott
Good luck!
Scott
#3
Join Date: May 2004
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First, get the codes pulled to see which one is flaking out. The easiest way without being able to do a power balance or coil stress test would be to simply walk that bad coil around to a cylinder that isn't misfiring to see if the misfire follows that coil. Just because an ignition coil checks okay resistance wise doesn't mean that it'll hold up under load.
#4
What if you don't get a code? I don't have that bad of a running problem, but at times a rought idle when cold, or it might take a couple cranks to fire up(happens about 3 out 10 times) I had changed plugs, boots, IAC, cleaned the TB. No codes, changed programs with my programer, changed fuel filters. I did notice that the blades on a couple of the coils had a slight greenish glaze.
Rob
2000 5.4L Exp
Rob
2000 5.4L Exp
#5
#6
Does anyone know if there is a TSB on the COP's and where to find a free copy?
I have an 01 SCrew 5.4 and had one go bad at about 20k - dealer misdiagnosed first and got it right the second time. Recently at 78k I had another go bad while on a trip - limped into a dealer who took me for $400 to replace another COP. Now I have the early symptoms of another going bad.
Is this a horrible design? Should Ford replace for free? Just upset and wondering...
I really want to get +150k out of this truck, but don't really have the time to mess with this issue every few weeks!
Are they easy to replace once the culprit is identified?
Thanks!
I have an 01 SCrew 5.4 and had one go bad at about 20k - dealer misdiagnosed first and got it right the second time. Recently at 78k I had another go bad while on a trip - limped into a dealer who took me for $400 to replace another COP. Now I have the early symptoms of another going bad.
Is this a horrible design? Should Ford replace for free? Just upset and wondering...
I really want to get +150k out of this truck, but don't really have the time to mess with this issue every few weeks!
Are they easy to replace once the culprit is identified?
Thanks!
#7
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#8
You are right...I gave up on 7 and 8...4 is bearable...Did you have to take off the fuel rails for 7 and 8?????
Oh...all of my coils look the same except for two of them...those two have a green motorcraft sticker on them...the rest are black. I am wondering which are the replacements and which could be factory?????
By the way, I switched around the 5 and 6 to see if it would throw a different error and no...it did not...so I now think that the coils are not the problem...and they checked out ok on the OHM test...
I'm stuck now and looking for a good place to take the truck...in Ohio...
-h
Oh...all of my coils look the same except for two of them...those two have a green motorcraft sticker on them...the rest are black. I am wondering which are the replacements and which could be factory?????
By the way, I switched around the 5 and 6 to see if it would throw a different error and no...it did not...so I now think that the coils are not the problem...and they checked out ok on the OHM test...
I'm stuck now and looking for a good place to take the truck...in Ohio...
-h
#10
#13
If you purchase a Haynes book it will tell you how to test the COP with an ohm meter. I noticed with my old truck 2000 F-150 w/ 5.4 it did not like anything but the motorcraft plugs that came w/ it originally. I also know O'Reilly's has a COP by borg-warner that carries a lifetime warr. Good luck