What would Cause a Slight Miss in 5.4 Motor?

[Nalajr]

Hey all,

First off, I am very much an rank amateur when it comes to vehicle repairs and diagnosing problems. I need all the help I can get, believe me.

OK, I have a 2003 Eddie Bauer with 110K on it. About 4 years ago I had a couple codes come up about 6 months apart and when I took it to the local parts store they told me that the codes meant I had a problem with one of the cylinders and needed a replacement of the Ignition Coil I had a family member do it for me cause I had no clue. Both times it cleaned it up and it ran fine.

In the last year, maybe 2, every now and then I will notice a slight miss when accelerating from about 15 mph to maybe 45 mph. It never happens when I am overtaking a slow vehicle or when I really press on the gas pedal. It will miss just a slight bit during that acceleration and then stop and sometimes it will repeat the next time I am at that speed and am speeding up to be in the normal traffic flow.
It hasn't happened for many months but today I was on about a 30 mile trip across town and about 1/3rd of the way when I left from a light, I noticed the slight miss again. As usual it will just miss during that slight acceleration and quit. Today it done it several times. On the trip back however, it only did it maybe 1 or 2 times and that was it. I could get it in tomorrow and drive across town or down the road to McDonald's and it might not do it again for 6-8 months, maybe a year. Today is the first time I have felt it in probably 8 months or more.
There are NO CODES being triggered.

I don't know if this would be a factor, but right before this started happening, my tank was on E and I pulled in to get gas. I don't know what kind of gas this station uses and whether it's good gas without much corn alcohol or not.

I have thought that I should probably replace all 8 of the ignition coils and plugs, but I can't do it and I don't know a reliable mechanic here that I could get to do it without being charged a TON for it. I think FORD wanted like $750 to replace them all, if I remember right from 4 or 5 years ago when I talked to them. My family member that did it for me last time is in poor health and he just can't do things like he could.

Can you all give me an idea of what might be the cause of this intermittent slight miss? Could it be the gas this time? Is there any significance to it happening only at low speed acceleration rather than when it has a stronger load on the engine like when overtaking a car going 55 mph?

Any ideas and suggestions would be appreciated. Thank you all kindly for your time and any help you care to give me.

Larry

 

[Bedrck47]

When was the last time ALL of the plugs were replaced?

 

[brick]

Probably an ignition coil going bad. Check the hoses going to the heater for leaks. They run above the rear coil packs, and if they leak onto the coils the coils fail.
When no code is present, your mechanic can run a scan and look for the cylinder miss-fires to identify which coil packs are the problem.
brick

 

[Nalajr]

Bedrck47, to my knowledge all of the plugs have never been changed. Now I cannot say for 100% sure as my Dad owned the vehicle and after he passed, I took it over and kept it. He maintained it really well and I think he bought it when it was 2 or 3 years old and probably 40K on it.

When I drove it a few hours ago the miss wasn't as noticeable as it was the day before. This has kinda been the pattern over the last couple years. It would start the slight miss and go for a week or so and then everything would be A-OK for several months or more and then I'd get another spell of the missing again.

For my own piece of mind, I would feel much better getting behind the wheel of it and going on an extended drive if I had new plugs and ignition coils in it. My problem is that I don't know if I can do it. I'm pretty sure I can get to 1/2 of them, but the ones at the back like #4, #7 and #8, I just don't know if I can get to them to change them out. I am also very worried about whether the plugs are going to break or the threads will strip out. I have read all sorts of horror stories about getting the plugs out on these older Expeditions with the 5.4 engine. That's what scares me cause I'd be in a world of hurt if that happened.

Last thing, I am likely going to go ahead with the Ignition coils and plugs. I am going to talk to my family member and see if he is at all able to help me and if not, I'm going to have to really study and see what I think and whether things will have to be taken off just to get them out of the way to allow me access to the coils. I'm not very adept at mechanical stuff when it comes to cars. In fact, this will be the first time I have ever tried to do something on an engine if I attempt this.

Can you all suggest a brand of coils for me to use as well as plugs? Would it be best to use the Motorcraft plugs from the FORD dealer? When I look on Amazon and Ebay I see all kinds of different brands of coils that range in price from $10 each all the way up to $75each for genuine Motorcraft Ignition Coil replacements.

What would you suggest? Any that you have had good luck using?

Thanks again.
Larry

 

[Bedrck47]

I would at least replace the plugs and the boots The boots are the part that connects the plug to the coil.

There are some very good videos on you tube about changing plugs for the 03/04 expeditions.

The main thing with the plugs is to make sure they are torqued to specs when installing new plugs.

 

[Habbibie]

I would at least replace the plugs and the boots The boots are the part that connects the plug to the coil.

There are some very good videos on you tube about changing plugs for the 03/04 expeditions.

The main thing with the plugs is to make sure they are torqued to specs when installing new plugs.

I strongly agree with his statement, the broken plugs are a problem on the 05-06 model years with the 3v motors, not applicable to you.

Getting access to the back plugs isn't actually hard, for cylinder #3 & #4 (passenger side) I strongly recommend you disconnect the battery (1-10mm on positive side, 1-8mm on negative) and remove your ECU out of the way(4-10mm bolts), also remove the bracket for the ECU (3-10mm bolts), use zip ties or equivalent to secure the ECU wiring harness out of the way.
After unplugging the connectors to the coils and possibly some to the injectors as well, you'll need a 7mm socket to remove the screws holding the coils, then either a 5/8 or 9/16 (05-06 uses 9/16 socket, not sure for 03-04 but it's either one of those sizes) spark plug socket to remove plugs. Torque to 28ft lbs, using antiseeze on the threads doesn't hurt. Use dielectric grease and fill/cover the opening on your New coil boots is recommended also. Reverse for reinstallation.

The driver side, cylinder #7 & #8 are much easier to access, you will have to remove your air intake held by a clamp on the throttle body (flat head screw) and rubber plugs on the fender side that you just pull up on to release, after that unplugging connectors and some vacuum lines is self explanatory, reverse for reinstallation. The use of zip ties is not needed on this side. Using dielectric grease on the electrical connectors is also recommended for both sides.

Tools you'll need:
3/8 drive ratchet
3/8 drive torque wrench (set at 28 ft/lbs)
6" extension
3" extension
9/16 or 5/8 spark plug socket
10mm socket
8mm socket
7mm socket
Flat head screw driver
Zip ties
Wire cutter to cut zip ties
Latex gloves keeps your nails from turning black.
A small bottle of antiseeze
A small bottle of dielectric grease
(I say bottle cause you'll need more than a few of those cheap pouches AutoZone sells)
Something to stand on to reach the back plugs (im 6'4 and even I need this)

Borrow, rent or buy a torque wrench, this tool is extremely important for this job.

Use antiseeze on every bolt you take off and antiseeze on every connector & boot you unplug,

When removing the battery terminals please watch out so you don't touch the positive and negative with the ratchet, use a rag or a towel and keep on terminal covered.

Estimated time is 90-180 minutes depending on your skill level and available tools.

.054 is the correct gap. Use only the Motorcraft double platium replacements for the best results.

This is an easy job in my opinion, just takes time.

I like megnatic spark plug sockets much better than rubber insert style, either that or securely tape the socket to the 6" extension.

There's a 99% chance this will eliminate your occasional mis.

 

[Bedrck47]

Something I would suggest

If you have a You Pull It Yard nearby Go and find a expy 03 or 04 And remove the plugs This will give you some idea as to what it takes to do the job and if you break anything it will be a good learning experience. You don't need to bring the plugs back This is just for practice

Once you get all the plugs out Then put NUMBER 3 and 4 and 7 and 8 back in as they are the hardest

Also don't worry if you loose any bolts as its just a parts vehicle but I would put a few in my pocket especially the ones for the coils

 

[stamp11127]

Just so you know the OP had a family member replace an ignition coil. He/she may not understand what you are saying to do. And I doubt they have a torque wrench. So........

 

[Habbibie]

Just so you know the OP had a family member replace an ignition coil. He/she may not understand what you are saying to do. And I doubt they have a torque wrench. So........

Well this is the best we can do to help, its not like were right there beside them holding their hands, a proper question was asked and a proper answer was given. I'm sure if the OP can navigate this website he can navigate his/her way to google and YouTube to view videos and some "how to use a torque wrench"

 

[ChrisOIFdoc]

Well this is the best we can do to help, its not like were right there beside them holding their hands, a proper question was asked and a proper answer was given. I'm sure if the OP can navigate this website he can navigate his/her way to google and YouTube to view videos and some "how to use a torque wrench"

 

[Nalajr]

Thank you all for the help and suggestions. I don't know if there is a torque wrench in the too l chest, I haven't seen one. There is one of those auto parts stores here that lets you use tools and then return them when you're done. I could always do that, I guess. Better than buying a torque wrench for this one project.

One of the problems I think I will have on this project is getting into the motor and back to the areas that I would need to access the plugs next to the firewall. I would have to find something to stand on like maybe bags of mulch stacked on top of each other or something sturdy. I can't do it standing on the ground because of the permanent back and neck problems I have to deal with.

As I sat today I thought about all the things I need to do on this vehicle that I am now going to have to do myself since my family member has really bad COPD and just cannot function in this 100 degree Texas heat from 8am to 9pm every single day. Just about every day until the middle of September will have a temp of about 95 and humidity that makes it "feel like" it's about 105 or so, sometimes up to 110. So its tough to do in this heat. I was out today checking fuses in it and within about 10 minutes sweat was dripping off of me. It'd terrible.

But here's what I am going to do in the coming month.

1. Replace brake pads on front.
2. Replace Door Lock Actuator on both front doors
3. Detail car in and out
4. Tackle this plug and ignition coil job
5. Continue to try and find the problem of why my 4WD will not work any longer.

That's about all I can think of.

Thanks all for the help.
Larry

 

[Habbibie]

Does your rear wiper work?

Anyways tackle one thing at a time and let us know what the next project is after we can help guide you step by step

 

[Nalajr]

Hey guys. Thanks for all the help and advice.

Habbibie, yes, the rear wiper works. At least it DID the other day when I took it thru a car wash.

The last couple of days I have been driving it a bit and the slight miss has disappeared. If the past is any indication, it might be a year before I experience it again.....or 2 days. Just to be on the safe side though, I am going to change the plugs and the ignition coils. As it sits now, I want to go out on a road trip to BIG BEND national forest which is on the border of Mexico, Texas and New Mexico. It's said to be on of the best places in the world to go stargazing and look at the sky at night.

I'm gonna revise my list and just tackle the items as I come to them. I know I'll have to have help on most of them, especially on the plugs and ignition coils.

Last thing, the prices of the replacement ignition coils are all over the place. Some can be had for $50 per set of 8, while others are $400 per set of 8. I have no clue which ones to get that will give me trouble free service for a while. The really expensive ones are the MOTORCRAFT parts.
I also will need new plugs. Would it be wise to stay with the OEM plugs rather than go with any other plugs or does it make a difference what plugs you use as long as they are correct for the model and set up right?

Please give recommendations for both of these parts please.

Thank you all.
Larry

 

[5star]

Plugs?

 

[ExpeditionAndy]

Hey guys. Thanks for all the help and advice.

Habbibie, yes, the rear wiper works. At least it DID the other day when I took it thru a car wash.

The last couple of days I have been driving it a bit and the slight miss has disappeared. If the past is any indication, it might be a year before I experience it again.....or 2 days. Just to be on the safe side though, I am going to change the plugs and the ignition coils. As it sits now, I want to go out on a road trip to BIG BEND national forest which is on the border of Mexico, Texas and New Mexico. It's said to be on of the best places in the world to go stargazing and look at the sky at night.

I'm gonna revise my list and just tackle the items as I come to them. I know I'll have to have help on most of them, especially on the plugs and ignition coils.

Last thing, the prices of the replacement ignition coils are all over the place. Some can be had for $50 per set of 8, while others are $400 per set of 8. I have no clue which ones to get that will give me trouble free service for a while. The really expensive ones are the MOTORCRAFT parts.
I also will need new plugs. Would it be wise to stay with the OEM plugs rather than go with any other plugs or does it make a difference what plugs you use as long as they are correct for the model and set up right?

Please give recommendations for both of these parts please.

Thank you all.
Larry

Hi Larry,

You definitely want to go with the OEM plugs, by all accounts they work better than anything else. You'll get all kinds of opinions on COPs, but for my money you get what you pay for. I'd buy the Motorcraft ones, you can't go wrong there. Others will no doubt have different opinions. Make sure you get the full kit with the wires that connect the COPs to the Plugs and use diaelectrical grease to keep the galling down.