I really don't want to take it to a dealership anyway. I'm pretty mechanically inclined and am willing to try and tackle it myself. I've just heard some horror stories about the rear plugs being a PITA to get to without the right tools and such. I have a code reader, so will "push" the engine to throw a code. I'm driving to the OBX in a week and really would hate for the COP to finally throw in the towel on the way there or coming back. 650 miles round-trip. Thanks for the advice.

 

It is so ez that I found my bad COP and replaced it and I'm a bit handicapped. More trouble finding it than fixing it.

 

yes #4 is a pita
get a mech to do it...much easier...these guys have all the extentions and swivels to do it quickly
some of the others are easy to get to
also be sure whoever does it puts PLENTY of dielectric grease on/in the boot and on the elect conn to the COP

btw wait till you are almost home and then give it hell
try to keep it at the same speed that it is shuddering at
took me about a month before it finally threw a code

 

I spent some time under the hood tonight looking things over. Do you have to remove or move the fuel rails out of the way to get the COP's and plugs out? Mine look like they'll interfere with the removal of anything. I vaguely remember a post awhile back about how to change out plugs and COP's, but haven't been able to locate it. Does anyone remember the post I'm thinking of or can give me the link to it?

The engine was really shuddering today, so I'm hoping the COP in question goes bad here soon and I can obtain a code before my trip next weekend.

 

CHANGING SPARK PLUGS ON A 5.4
Plain and simple, the 5.4L is a high tech engine. While the block on the 5.4L and 4.6L are pretty much the same, the structure and technology of the engine is entirely different. While the spark plugs on a 4.6L can be challenging, it is still relatively straight forward. Spark plugs are where spark plugs typically are, the spark wires run to a distributor like you’d expect in any vehicle, etc.
The 5.4L features, as well as other high tech features, the lack of spark plug wires. Rather then having spark plugs mounted on the sides of the engine, wires running to a distributor, the spark plugs in this engine are on top of your engine, and are connected directly to the ignition coil. Everyone has a different way of changing out the spark plugs, and everyone says their way is the best. I will not try to compete with everyone, because each method has its own advantages. For example, some people don’t take off the fuel lines, which takes that off the installation but it makes removing the coils more difficult if not nearly impossible. Using my method I try to make it as easy as possible and prevent breaking anything while in there.There is also a lot of debate as to what spark plugs are best. There are some who swear by high-end spark plugs such as Bosch Platinum +4’s or Denso plugs, and some that swear by standard Ford Motorcraft plugs. I decided to use the same OEM plugs that came with the truck, Motorcraft platinum plugs. You can be assured when using OEM equipment that you shouldn’t have any problems that you can blame on the plugs.
Tools you will need for this job are a 7mm, 10mm, 5/16", 5/8" deep and 5/8" spark plug sockets. The spark plug socket has a special rubber fitting inside, which grabs on to the spark plug, which is required to remove the recessed plugs from our engine. You will also need 1/4" and 3/8" universal joints and various 1/4" and 3/8" extensions. A spark plug gap tool can be purchased for under a dollar, and will prove valuable when setting the gap on the spark plugs. You will also need a tube of anti-sieze to apply to the threads of the new spark plugs. For different jobs you may need needle nosed pliers, a flat head screwdriver and other various tools.
PROCEDURES:
Always be sure to remove your negative battery terminal prior to doing any work on the truck! Part of the procedures requires some gasoline spilling into the engine, as well as many points where a metal tool could come in contact with the body and an electrical source causing spark or worse, fire or personal injury. To avoid any such disasters, it is much easier and safer simply to remove the negative terminal prior to any work being done. Also, as a caution, do not over torque the spark plugs or the bolts attaching the coils to the head. Unfortunately I did so and ended up making the project much harder when I snapped a bolt off that held the coil to the head. Remember that you will always do much more damage by over tightening a bolt too much then you would by not tightening it enough.

1. Using your 10mm and 5/16" sockets, remove your throttle body cover. This will give you better access to what you are working on. Also, I found it much easier to remove the bracket attaching the power steering pump for easier access to the plugs. This bracket is attached with three 5/16" bolts, and can be dangled out of the way, as it connects to one of the vacuum lines.

2. Using your 5/16" socket, remove the two bolts attaching the fuel line to the head of the engine. Once sockets are removed and set aside, pry the fuel line CAREFULLY away from the fuel injectors. Use caution to prevent damage to the injectors and the o-rings around the injectors. Beware that some gas will spill out when you remove the lines. Because of this, smoking or having an open flame (or even a hot trouble light, etc.) while working on the spark plugs is a definite do not do! If you ever want to upgrade to better injectors, now would be a good time to do so, you can simple pull them up to remove them from the engine.
3. Pry the fuel line up and out of the way as far as you can without bending or breaking the line.
4. The coil’s are mounted with 7mm bolts, in between the injectors. If you aren’t sure which is which, the injectors are orange and have blue o-rings, the coils are black and typically have yellow sticker son them (see below picture). Depending on the location of the coil, you may find it easier to use a univeral joint or a series of extensions to loosen and remove the 7mm bolt. After loosening and removing the bolt, you can unplug the electrical connector from the coil, and pull the coil out of the head.
5. After removing the coil, you can begin work on removing the spark plug. I find it to be a good trick to use to blow some compressed air in the hole or vacuum the hole out, to loosen any trapped dirt and prevent it from dropping into the engine.
6. Because the spark plug sits so recessed in the head, it is a good idea to attach a 6" or 9" extension to your spark plug socket. You may need more extensions so make sure you have enough prior to starting the project. It is also important to note that the spark plug does not sit perfectly vertical, it is at an angle, facing the rear of the truck. If used properly after removing the spark plug, the spark plug socket should hold on to the spark plug, allowing for easy removal.
7. Once you have removed the old spark plug, it is time to prep your new spark plug for installation. This involves gapping the spark plug and placing anti-sieze into the threads. To gap the spark plug, use a spark plug gap tool (can be bought for about a dollar at any auto parts store), and slide the spark plug along the tool until you reach the desired gap measurement. For the F-150’s, the recommended spark plug gap is between .052 and .056 inches. You can also use a feeler gauge for a more precise measurement. You should place some anti-sieze on the threads to not only make it easier to remove next time you do the plug, but also helps keep the seal better then without anti-sieze, and prevents rust from forming in the head.
8. Once your spark plug is prepped, it can be installed. Unlike some spark plug jobs, reinstalling the spark plug is just as difficult as uninstalling it. Reason is you can’t just put the plug back in the spark plug socket and reinstall it. If you do so, the spark plug socket will grip on to the plug, and you won’t be able to get your socket out. The method I used was placing the spark plug in the spark plug socket slightly, but not into the bolt portion of the plug. By just placing the plug in deep enough so the socket won’t drop the plug, you can get the threading started, but remove the tool after a few turns with the socket. After starting the threading with the spark plug socket, switch to the standard 5/8" deep socket and torque down. Because the standard socket won’t grip on to the spark plug, you will be able to pull it away from the spark plug after tightening it down.
9. After the plug is installed and tightened down, reinstall the coil, reconnect the electrical connector for the plug, and reinstall the 7mm bolt. Repeat procedure for the following plugs.
10. Some plugs you will find are easier to replace then others. As mentioned previously, I had to use several extensions with a universal joint to safely remove the rear spark plug.
11. Once all spark plugs on one side have been replaced and all coils are bolted down, you will need to reinstall the fuel line. To do so, carefully place the fuel line into position over the fuel injectors and snap over the injector o-ring. Secure with 5/16" bolts that were removed previously, and visually inspect for tightness.
12. Repeat the same process for the spark plugs on the other side.

 

If you have access to a scan tool (or a laptop running OBDII software with interface), you can go in and look at your individual cylinder misfire counts and see where the misfire is occurring so you can identify the problem cylinder.

The computer is keeping track of this data and you can use it for diagnosis long before the system posts a CEL and a fault code.

Cylinders 1, 2, 3, 5, & 6 are easy. The other three are a PITA.

Steve

 

I found my datalogging program has the capability of reading those PIDs. I found that after I went thru replacing COPs till I found it. If you have a question about the condition of a stock COP the resistance reading is 5.6 on the 300k scale. You measure from the COPs output to either of the input terminals. A lower reading means windings have shorted producing a weaker spark but not enuff to throw a code.

 

Bumping this up because I'm working on a friend's 2000 Expedition (4.6L V8, Auto, 4x4, 136K miles on the clock)

He has a receipt for diagnostics indicating a code P0303, P0306, and P0308... Cylinders 3, 6,and 8 misfiring. I cleared the codes and ran the engine, only came back with 6 and 8. It took forever to start, but once it did, it held a rough idle. It died when I put the transmission in Drive though.

1st Question: Based on the mileage and the codes, should I replace ALL the coil packs? Could it just be bad plugs and the shop was trying to get something extra out of him? What's the life expectancy of these coils?

2nd question: Do I HAVE to remove the fuel rails? Or is there a way to get the coils out without touching the fuel rails? (I've had bad experiences with tearing up o-rings. The rubber is almost 10 years old and exposed to fuel, how pliable can it be?)

 

With 136K, have the plugs been changed yet? If not, it might be a bad plug instead of a bad COP. I would go ahead and replace all of the plugs and COPs just to avoid future aggravation. A set of 8 COPs can be bought off eBay for around $100.

Some claim to be able to replace the COPs without removing the fuel rail. When I did mine I pulled out the fuel rail and replaced all of the o-rings. I think the set of 16 o-rings was under $5.

 

Hi, just had some of this happen to me. Rough idle and then bad power finally set a code, it was CYL 3 misfire. On my 2001 only have 68,000. Took a chance and just replaced the COP myself, seems fine, ran about 8 miles and NO codes. Got code cleared at Advance Auto, so if anything new comes up I will know.

Hope this helps someone

Mike

 

Great write-up by Kaboom10--thanks, I'll be keeping that one,as my Expy has 123k on it and no cop problems yet.

 

Good write up. Except why did you move fuel lines and such? I changed all mine without a single swivel anything, or removing fuel lines. Get yourself and a smaller handled 3/8" drive wrench with a small 7mm socket on it and a couple different length extensions, nedle nose pliers (in case the boot comes off the coil and stays on the plug)and that's all you need! The ones in the back are a pain, and some F bombs were dropped for sure. the ease of others makes up for it! (Changed #5 plug and coil in less than 5 mins!


MAKE SURE YOU HAVE A TELESCOPIC MAGNET!!!! YOU WILL DROP A BOLT OR TWO!