Notices
1997 - 2003 F150 1997-2003 F150, 1997-1999 F250LD, 7700 & 2004 F150 Heritage
Old 11-12-2014, 05:54 PM
How-Tos on this Topic
Last edit by: IB Advertising
See related guides and technical advice from our community experts:

Browse all: Electrical Guides
Print Wikipost

How to replace your 4.6L & 5.4L spark plugs

 
  #16  
Old 09-10-2003, 07:38 AM
GA boy
GA boy is offline
New User
Join Date: Sep 2003
Posts: 6
GA boy is starting off with a positive reputation.
How to replace your 4.6L & 5.4L spark plugs

Don't know the exact conditions of your boots getting stuck, but that reminded me of another tip. A set of boot pliars (my name for them) are great for removing stubborn boots. When removing the boots, you have to pull and twist. Sometimes this is not that easy to do, but you have to twist more than you pull. Get a small tube of the anti seize lube and be sure to use it on the installation.

These wires are incredibly expensive. They should be handled with care and caution.
 
  #17  
Old 09-13-2003, 11:14 AM
HotF150
HotF150 is offline
New User
Join Date: Jul 2003
Posts: 7
HotF150 is starting off with a positive reputation.
How to replace your 4.6L & 5.4L spark plugs

I don't know if this would work for the COP models, but for my 4.6L that has just a boot and wire on the plug, I found that wrapping a length of twine around the top of the boot and giving it a good pull helped in getting the boot off of the plug. It even worked on the #4 - popped right off after I'd already spent about 30 minutes trying to twist it off the plug.

This is a great thread!
 
  #18  
Old 09-21-2003, 01:21 AM
pro3qtr
pro3qtr is offline
Elder User
Join Date: Apr 2001
Location: MT
Posts: 503
pro3qtr is starting off with a positive reputation.
How to replace your 4.6L & 5.4L spark plugs

A good rule of thumb is to check the plugs at 50K

My stock plugs where wasted at 45K !!!

Check your heater hose above #4 plug, most all are LOOSE!!

My #4 was change before and the second plug was rusted up !! From the hose leaking.
 
  #19  
Old 09-29-2003, 12:16 PM
GrandBlanc
GrandBlanc is offline
New User
Join Date: Jun 2003
Posts: 12
GrandBlanc is starting off with a positive reputation.
Racerguy

If your looking at the 5.4L engine from the front of the vehicle, how are the coils numbered? Odds on left evens on right? Any help would be cool.
 
  #20  
Old 09-29-2003, 07:49 PM
Racerguy's Avatar
Racerguy
Racerguy is offline
Post Fiend
Thread Starter
Join Date: Aug 2002
Location: BC, Canada
Posts: 12,674
Racerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to behold
The furthest ahead cylinder is #1, the front one on the passenger's side. It is 1,2,3,4 on the passenger side, 5,6,7,8 on the driver's side.
 
  #21  
Old 11-21-2003, 12:54 AM
macgyvr's Avatar
macgyvr
macgyvr is offline
Freshman User
Join Date: Jun 2003
Location: Indiana
Posts: 45
macgyvr is starting off with a positive reputation.
I'm bringing this back up to the top as I printed this thread for reference as I changed the spark plugs on my truck tonight. This thread IS a MUST read for anyone getting ready to change their plugs.

The article is printed here: https://www.ford-trucks.com/articles/2003/10.php

but this thread still has more info than what got included in the article. you'll have to excused me as I got the spark plugs done and then have drank until i can barely see/type straight....

The number 7 and 8 are the worst. I cussed until i couldn't cuss no more at them. You either need a socket wrench that has a flex head or a 7mm gear wrench for those damn COP bolts. That number 7 is an SOB!!!!!

The spark plug socket with the four inch extention then the universal then a longer extension worked perfect for me in getting the spark plugs out...

I had a lot of gunk in mine and used a shop vac w/ a piece of heater hose duct taped to the end to suck the crap out of the hole before took the spark plug out, this helped termenously in getting the gunk out before you put the new spark plug back in.

After reading and rereading this thread, since this is the first time i was working on the f150 5.4 motor, it took me 1.5 hours to do the pass side and 2 hours to do the drivers side. i'm pretty good with the wrenches and have pulled serveral motors but these are the most time consuming and makin ya cuss like a sailor spark plugs that i have ever run across.....

even after all that at 60k, i'm ready to do them again whenever i managed to get 120k on the motor.....

mac 'put the reccomened platium motocraft plugs in' gyvr
 
  #22  
Old 01-19-2004, 02:07 PM
PaulC
PaulC is offline
Posting Guru
Join Date: Sep 2002
Posts: 2,297
PaulC is starting off with a positive reputation.
Swapping a suspected bad COP with a known good one sounds like a good diagnostic method to me. If the misfire migrates to the cylinder with the old #4 COP, you've got it.

BTW, the most common reason for demise of the COP on the #4 cylinder is leaking antifreeze from the heater hoses poised over that section of the engine. I suggest that you ensure that you don't have any antifreeze leaks in that area before you swap/replace COPS.
 
  #23  
Old 02-28-2004, 06:01 PM
richkrik
richkrik is offline
New User
Join Date: Dec 2003
Posts: 2
richkrik is starting off with a positive reputation.
Talking I got my Iridium Plugs in today

Well, I am now a memeber of the "replaced the plugs in my F150 5.4" club. It wasn't nearly as bad as I thought after reading this thread. If you are going to do it, here are some good hints, besides what you read here:
--While it may be possible to pull the COPS without removing the injector rail, I can't imagine not doing it. It's so simple. A couple of screws, coupla grunts, and up she comes. Remember to relieve fuel pressure before you do this. Autozone has a $30 fuel pressure meter with a relief valve/hose to drain fuel in rail. Also remember to plug injectors and rail when blowing all the crud out of the plug hole.
--I taped some vacuum hose on my blow gun to get the dirt out of the plug holes. Very surprised at the dirt/etc. in there.
--I used more vacuum hose to put on the end of the new plugs to use as a device to start the plugs into the threads. Very handy.
--The Denso Iridiums I bought ALL had to be regapped to .050, their claims to be pregapped notwithstanding. Make sure you check yours.
--Torqued the plugs at 14ft/lbs.
--I removed tires and lowered my truck on to a coupla blocks of wood to get my big belly over the front of engine compartment. When I raise it six inches in the future, I'll have to do this AND use a stool.
--It REALLY helps to have LOTS of esxtension bars, and especially a locking extension bar to hold your plug socket, so it doesn't come off when pulling it out.
--Only had one boot get stuck on me, got it out with some really long nosed pliers. Won't happen again as I used dielectric grease on the new ones.

Hope this helps, and thanks to everyone for all the good ideas here. I won't be nearly as hesitant next time.
 
  #24  
Old 03-14-2004, 06:04 AM
brownjc
brownjc is offline
New User
Join Date: Dec 2003
Location: Brunswick, Maine
Posts: 3
brownjc is starting off with a positive reputation.
Plug Wires and COP's

This thread on changing spark plugs has been very informative. My '99 has 112,000 miles. I changed plugs last year, but I am wondering about wires and COP's. I think they are original. Should these be changed out on a truck with this mileage? Truck is running rough and "Service Engine Soon" light has come on. I believe the trouble is #4 spark plug is either loose or is not sparking for some reason.
Thanks
 
  #25  
Old 03-14-2004, 11:01 AM
Racerguy's Avatar
Racerguy
Racerguy is offline
Post Fiend
Thread Starter
Join Date: Aug 2002
Location: BC, Canada
Posts: 12,674
Racerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to behold
Have you had your truck scanned to see what code caused the light to come on? If it is misifre related it will tell you which cylinder the problem is.
What size engine in your truck? The 4.6 has plug wires, the 5.4 has COPs. COP stands for Coil On Plug. Each spark plug has it's own coil sitting on top of it and no spark plug wires.
 
  #26  
Old 03-14-2004, 05:39 PM
brownjc
brownjc is offline
New User
Join Date: Dec 2003
Location: Brunswick, Maine
Posts: 3
brownjc is starting off with a positive reputation.
Racerguy - thanks for the response - no I haven't had the computer scanned yet. I have the 4.6 engine, so now I understand I don't have COPs. I took the #4 plug wire off, made sure the spark plug was tight, cleaned the plug boot and reinstalled. The truck is running smooth now. So now my two questions are:

1. With 112,000 miles, should I replace plug wires? I'm not familiar with these newfangled ignition systems with no distributor cap/rotor to replace!

2. If the problem is fixed, will the "Service Engine Soon" light go out by itself?

3. If not, any recommendation for a ceap handheld unit I can buy to read/reset my own codes?

Thanks - your responses on this board have been invaluable.
 
  #27  
Old 03-14-2004, 11:03 PM
Racerguy's Avatar
Racerguy
Racerguy is offline
Post Fiend
Thread Starter
Join Date: Aug 2002
Location: BC, Canada
Posts: 12,674
Racerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to behold
You're welcome
I would think that replacing the plug wires would be a good idea. The stock wires are good for a long time but sometimes a bad plug can be hard on a wire as it stresses the wire more if the spark has a problem going where it should go. The plug wires on these are a bit of a pain to replace but if you do one at a time you'll be ok.
The Check Engine light will go out eventually but you can clear the code and turn the light out by disconnecting a battery terminal for 10 minutes. If you do that and the light comes back you know you've got a problem that you should get checked. if you have an Autozone there apparrently they will scan the system for free. If you do get it scanned make sure you write down the code number and not just the description. If you post a code on here we can help you get it figured out.
As for a cheap scan tool I dont have any good suggestions but if you look around in the forum you'll find lots of opinions on what ones are good.
 
  #28  
Old 03-15-2004, 07:59 PM
scprjamie
scprjamie is offline
Freshman User
Join Date: Jan 2003
Posts: 26
scprjamie is starting off with a positive reputation.
160mi no problem

Have a 97' F-250 with 160,000mi with the original plugs. Lucky so far I guess. What,s the worst thing that could happen as a result of not changing them?? No idle problems so I assume keep running them until I have a problem. Thanx in advance for your reply.
 
  #29  
Old 03-15-2004, 11:56 PM
Racerguy's Avatar
Racerguy
Racerguy is offline
Post Fiend
Thread Starter
Join Date: Aug 2002
Location: BC, Canada
Posts: 12,674
Racerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to beholdRacerguy is a splendid one to behold
You can't always feel a slight misfire but your old plugs might be doing that which will hurt gas mileage some. Old plugs that are worn can have very big gaps for the spark to jump which puts extra stress on the plug wires and/or coils.
Even if it feels like it's running ok I think it will probably run better after you replace them.
 
  #30  
Old 03-16-2004, 02:56 AM
deckofwood2002
deckofwood2002 is offline
New User
Join Date: Jan 2004
Posts: 15
deckofwood2002 is starting off with a positive reputation.
spark plug change

i change plugs on the 4.6,5.4 and 6.8l's all the time but fortunately the engine is on a engine cart due to i work in a dyno lab.what i found very very useful are the locking extensions.it's quicker and you don't lose your socket in the head.although the 3v versions of the modualar motor you need a 9/16'' socket to remove them,so what i did is remove the rubber boot from the inside of an extra 5/8'' socket and stuffed it into the 9/16'' socket.WORKS GREAT.
 

Thread Tools
Search this Thread
Quick Reply: How to replace your 4.6L & 5.4L spark plugs


Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.