Changing Spark Plugs on 1998 Ford Expedition 5.4L (Eddie Bauer)

[jmsigler2]

Problem:
My engine light just came on this week.
Vehicle has 65,000 miles.
Auto shop diagnosis is that cylinder number is having firing problems.

Actions:
First step by choice is to change the spark plugs. I purchased some high-end performance replacement plugs.

I am looking for advice on sources of information on how to replace the plugs. Do I have to purchase a dealer repair manual? Autozone does not have a manual for this yet. I assume their is a Chilton Guide. Can we find this information on the web now?

James
Dallas, TX

[jiggly]

Originally Posted by jmsigler2

Problem:
My engine light just came on this week.
Vehicle has 65,000 miles.
Auto shop diagnosis is that cylinder number is having firing problems.

Actions:
First step by choice is to change the spark plugs. I purchased some high-end performance replacement plugs.

I am looking for advice on sources of information on how to replace the plugs. Do I have to purchase a dealer repair manual? Autozone does not have a manual for this yet. I assume their is a Chilton Guide. Can we find this information on the web now?

James
Dallas, TX

one of your coil packs might be FUBR, you may have to replace one or more to fix the problem, also, to check your spark plugs, remove the coil pack, then you will see the spark plug .
as for replacing spark plugs, i use motorcraft .. and my expdy runs like a champ.

[mrfedex001]

I don't know if you are aware that each cylinder has a ingnition coil. I didn't know this and I was having the same problem. Each one is about $40 so you want to be sure wich one is bad......

[DaveHus]

I agree with the coil problem.
I have a 99 and have had to replace a coil pack on 3 different occasions, when the engine starts misfiring. Only 5 more to go.

[mikestbird443]

anyone know the factory gap for the spark plugs for a 97 with the 5.4l

[kepot111460]

You can change all 8 plugs i did it myself. the key is the ratchet configuration for the cylinders in the back. you need 2 extensions and a swivel and you can get to them. After I changed the plugs the light went off and no problems since. Your coils are probably good, moisture does get down there and i bet your plugs are pretty ugly like mine were.

[epm103]

when you have the coils out check the Ohms with a meter. check across the B+ contact where the connector is and the spring where it connects to the plug it should be 5.5 Ohms. If it is less it will miss, I have noticed around 5.3 causes issues. label them when you take them out and check them its easy to forget which one you did or didn't check.

[yhc]

Good afternoon.

I was able to change out all the plugs except for 3 & 4 yet. What is the best way to access them work on them? Do I need to disconnect any hoses, etc? If so which hose and how?

Thanks for your time in advance.

Regards,

yhc

[vann]

1999 5.4L I have an expedition that is stumbling now on acceleration and getting worse. I have found the coils and plugs and pulled the first two on the Pass side. What I don't know is how much stuff do I have to take off to get to all eight? Finally got the first two coils and plugs out on both sides. coils test at 5.35 to 5.45 ohms and the plug gaps are .063 to .065! What are the odds that the coils are bad?
thanks, vann

[bkf77]

[quote=jmsigler2;12425]Problem:
My engine light just came on this week.
Vehicle has 65,000 miles.
Auto shop diagnosis is that cylinder number is having firing problems.

The first thing I would do is mark the coil on the suspected cylinder. Then I would proceed to check the condition of the spark plugs. If you are pushing between 60k and 100k on the set of plugs, I would change them. The gap for the new plugs will be 1.32-1.42 mm (0.052-0.056 in). Try the spark plugs first. Check for moisture in #3 and # 4. When reinstalling the coils, put the marked coil in the front for easy access if you still have a problem. Do you know the code #? Coils are a common problem on the 4.6 or the 5.4 engine.

As far as removing the plugs, there is no easy way. Each coil has a 7mm bolt holding it in place. I unplug the coils and the injectors to gain some clearance. I use a 1/4 swivel socket and a long extension to get to most of the bolts for the coils. On #8 coil have a ext. magnet handy due to lack of room for your fingers. As for the plugs, you will need a variety of extensions to find a length that will work for you and a 5/8 plug socket. I use a short locking extension that way the socket doesn't stay down in the hole. Let me know if you need any more information.

Some of the other members who posted to your thread need to start there own. Makes it hard to answer your question with their's jumbled in also.