COP or something else?
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Elder User
Joined: Jul 2004
Posts: 637
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From: Media, PA
COP or something else?
I need some help. My '02 Expy 4x4, 5.4 developed an odd "miss" at a set RPM over the weekend and it's getting slightly worse. At first I thought it was the transmission slipping, but now I'm not sure. The issue happens most noticable when the trans is in O/D at around 50mph. RPM's are around 1200. The truck starts to develop a shuddering/missing symptom. Almost seems like a COP is going (cutting off spark intermittently). If I kick it down out of O/D, the miss goes away, as RPM's go up. The miss only happens at this certain RPM & trans gear. If it were a COP, wouldn't it be happening all the time? Could it be a partially clogged fuel filter? I checked the trans fluid level and it's fine, no burnt smell, nice pink color. The Expy has 91,000 miles on it. I'm really hoping it's not the trans going south. I know it's kinda hard to diagnose without sitting or driving it, but any help or advice on what to look for is greatly appreciated. 
Elder User
Joined: Aug 2004
Posts: 551
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Are you getting any codes? A restricted fuel or air filter can also cause these symptoms as well as a vacuum leak. Check the PVC tube for cracks or dry rot. You can try running some injector cleaner through your fuel system also. If the simple stuff doesn't solve the problem, then start looking at things like: plugs, boots, compression test, vacuum test, etc.
Fleet Owner
Joined: Apr 2008
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From: 0,0,1
That would be right about when the torque converter lockup kicks in. A tranny fluid and filter change might be in order.
Thread Starter
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Elder User
Joined: Jul 2004
Posts: 637
Likes: 4
From: Media, PA
Are you getting any codes? A restricted fuel or air filter can also cause these symptoms as well as a vacuum leak. Check the PVC tube for cracks or dry rot. You can try running some injector cleaner through your fuel system also. If the simple stuff doesn't solve the problem, then start looking at things like: plugs, boots, compression test, vacuum test, etc.
Thread Starter
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Elder User
Joined: Jul 2004
Posts: 637
Likes: 4
From: Media, PA
Makes sense. I usually have the fluid changed once a year because of the towing I do with the Expy. Never got around to having it done end of last year. Was planning on having it done here soon. Now would be a good time, I suppose. Thanks for the reply. I appreciate it.
Logistics Pro
Joined: Jan 2001
Posts: 3,740
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From: Central NYS
Quote:
<TABLE cellSpacing=0 cellPadding=6 width="100%" border=0><TBODY><TR><TD class=alt2 style="BORDER-RIGHT: 1px inset; BORDER-TOP: 1px inset; BORDER-LEFT: 1px inset; BORDER-BOTTOM: 1px inset">Originally Posted by ExpySport
The issue happens most noticeable when the trans is in O/D at around 50mph.
</TD></TR></TBODY></TABLE>
Hmmmm - that would also be right about where it switches from multiple strike spark to single strike. What is the make/condiction of the sparking plugs?
<TABLE cellSpacing=0 cellPadding=6 width="100%" border=0><TBODY><TR><TD class=alt2 style="BORDER-RIGHT: 1px inset; BORDER-TOP: 1px inset; BORDER-LEFT: 1px inset; BORDER-BOTTOM: 1px inset">Originally Posted by ExpySport
The issue happens most noticeable when the trans is in O/D at around 50mph.
</TD></TR></TBODY></TABLE>
Hmmmm - that would also be right about where it switches from multiple strike spark to single strike. What is the make/condiction of the sparking plugs?
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Thread Starter
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Elder User
Joined: Jul 2004
Posts: 637
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From: Media, PA
Quote:
<TABLE cellSpacing=0 cellPadding=6 width="100%" border=0><TBODY><TR><TD class=alt2 style="BORDER-RIGHT: 1px inset; BORDER-TOP: 1px inset; BORDER-LEFT: 1px inset; BORDER-BOTTOM: 1px inset">Originally Posted by ExpySport
The issue happens most noticeable when the trans is in O/D at around 50mph.
</TD></TR></TBODY></TABLE>
Hmmmm - that would also be right about where it switches from multiple strike spark to single strike. What is the make/condiction of the sparking plugs?
<TABLE cellSpacing=0 cellPadding=6 width="100%" border=0><TBODY><TR><TD class=alt2 style="BORDER-RIGHT: 1px inset; BORDER-TOP: 1px inset; BORDER-LEFT: 1px inset; BORDER-BOTTOM: 1px inset">Originally Posted by ExpySport
The issue happens most noticeable when the trans is in O/D at around 50mph.
</TD></TR></TBODY></TABLE>
Hmmmm - that would also be right about where it switches from multiple strike spark to single strike. What is the make/condiction of the sparking plugs?
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Logistics Pro
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From: Central NYS
Mountain Pass
Joined: Apr 2007
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From: St. Paul, MN
The shuddering is probably the tranny fluid asking for a change. It may look good to the eye, as mine did, but when it got changed the shuddering went away. Do all your maintenance & see what happens.
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Elder User
Joined: Jul 2004
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From: Media, PA
It's very hit and miss now. Didn't do it at all Wednesday, did it once or twice yesterday. Expy's going in the shop Monday to have the fluid & filter changed, along to have the fuel filter changed. I'll report back if this service fixes the shuddering. My gut is saying it will. Thanks to all for your replies thus far!
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Elder User
Joined: Jul 2004
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From: Media, PA
Expedition went in today for a complete transmission service and fuel filter change. The service write-up guy asked me why I was having the trans service done, and after telling him the symptoms, he agreed it was the trans needing a complete service. I picked it up this evening and took it for a short drive. The trans shifts much nicer and smoother now. I'll give it a better run tomorrow on my way to work and report my findings. 
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Elder User
Joined: Jul 2004
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From: Media, PA
I gave the Expy a good run into work Tuesday and it ran beautifully. No slipping/missing/skipping noises. However, this morning, it started doing it again, and it's now doing it every so often between 40 and 50mph. The engine still idles and runs fine.
I'm leaning towards just giving in and having all the plugs and COP's replaced now. I've seen COP's advertised on eBay for $109 for a complete set. I've seen different posts on here about what Motorcraft plugs to use, however. Can someone tell me which are the correct ones to use? Thanks. Not looking forward to this bill at all.....
I'm leaning towards just giving in and having all the plugs and COP's replaced now. I've seen COP's advertised on eBay for $109 for a complete set. I've seen different posts on here about what Motorcraft plugs to use, however. Can someone tell me which are the correct ones to use? Thanks. Not looking forward to this bill at all.....
Senior User
Joined: Oct 2007
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having had this shuddering problem 3 times now here is my advice
everytime it was a bad COP or plug
yes it only did it at certain speeds just like you said
yes no CEL no code
yes i changed the filter and serviced the trans just like everybody wants you to do
these engines are known to have COP issues after and sometimes before 100,000
what you have to do is really stress the engine when it starts to shudder to get it to give you a code or CEL
the Ford tech i know said that the engine has to run bad consistantly for a certain period of time for it to throw a code
once you get that CEL take it to Autozone and get them to read the code to give you the bad cylinder
most likely it will be #4(very common do to water dripping onto the COP)
buy a COP AND a plug
DO NOT just change the COP
for 3 bucks get a motorcraft plug and do it right
so far i have had to replace #4 #7 and # 3 ...i think, but my engine has 142,000 on it
DO NOT take it to the dealership to do this
it is too easy to do yourself or pay a mech 50 bucks to do it for you
i watched my guy do it all 3 times and it takes about 15 min for a mech to do it
everytime it was a bad COP or plug
yes it only did it at certain speeds just like you said
yes no CEL no code
yes i changed the filter and serviced the trans just like everybody wants you to do
these engines are known to have COP issues after and sometimes before 100,000
what you have to do is really stress the engine when it starts to shudder to get it to give you a code or CEL
the Ford tech i know said that the engine has to run bad consistantly for a certain period of time for it to throw a code
once you get that CEL take it to Autozone and get them to read the code to give you the bad cylinder
most likely it will be #4(very common do to water dripping onto the COP)
buy a COP AND a plug
DO NOT just change the COP
for 3 bucks get a motorcraft plug and do it right
so far i have had to replace #4 #7 and # 3 ...i think, but my engine has 142,000 on it
DO NOT take it to the dealership to do this
it is too easy to do yourself or pay a mech 50 bucks to do it for you
i watched my guy do it all 3 times and it takes about 15 min for a mech to do it