MilosF150

Hello all,

new to me 2004 F150 5.4V8 w/125k. I've been reading up on what needed to be done around the 100k mark and evidently plugs are one thing on the list.

So yeah, they break.

Any way to ID the plug from stock with it still in the motor.. I know... wishful thinking... just don't want to do work that doesn't need done.

redfishtd

Just try the easiest plug to get to and take it out . Read ford TSB on replacing plugs . Its a good Idea to have the Lisle plug extractor kit first . Check with Auto zone to see if they have it in your area on the lend a tool .
Original plugs are a bear if you don't gear up to do them . You must do a good job replacing them with oem the correct way . This engine very touchy about oem and proper installation . Nothing a willing guy can't learn to do on here.

650NutKase

Pulling 1 plug isn't always going to mean they've been done. A couple could have been replaced due to an isolated issue. Any time I get a used vehicle, I do ALL maintenance items that are due. This way, I know the job got done and got done right. Get the Lisle tool and read up on the TSB and watch videos. Select the method you feel most comfortable with. Good luck!

06'5.4

When i pulled all mine out the plug's all had a white hash mark on top of them...i was told they were done that way from the factory...

badwithcomputer

the hardest ones to get at are always the original ones...

SlowGrind

X2

This happened on my 07 while still under warranty. Dealership replaced 2 plugs at the same time. One was replaced with updated plug the other with old style 2 piece. I didn't have a clue until I changed plugs myself.

redfishtd

You guys are right someone could have put the wrong plugs in her and not changed the difficult ones . Even some shops skip difficult plugs .
I hate to put a newbie on trying to pull number 4 first that would put anyone off .
So we are back to engine build date on driver valve cover and maybe vin number . This year not an iffy year like the 08's .
2004 5.4 should be sp515 , pulling number 6 is just a guide to gear up for the difficult ones . Gives you the boot color and maybe the idea about the plugs .
At 125k it would be foolish not to do all boots /plugs . If you don't have the history you have to start fresh . Do drivers side first then you will have some experience for the more challenging passenger side .
http://www.amazon.com/Lisle-LIS65600...ord+sparkplugs
http://www.amazon.com/CTA-Tools-2385...ord+sparkplugs
http://www.amazon.com/Motorcraft-SP5...XBXH7H7NCJ46H#
DENSO 6718164 Complete Set; 8 Boots; 106mm Info
Original Equipment Replacement Part rock auto $25.79
Torque those in 25 foot pounds .

MilosF150

I found some notes on in the engine bay that shows oil changes every 3k-ish and a trans flush at 75k (now at 125k). This truck used to be used in a business so I think the maint schedual was followed at least a little.

I already did the oil (synthetic) and Motorcraft filter (Walmart has them for $5!). I figure next month I'll do plugs and COPS since they appear to be original (the COPS).

Have the plug puller tool but hope its not needed.

techrep

iTrader: (1)

Why would you replace COP's that are working just fine.. waste of $400.. replace the boots and springs and the plugs.. go from there.

Jojodapyro

MY suggestion is to use air tools. Mine were about the same age and mileage as yours are, and they all came out fine. I did have to remove the ECU off the firewall to get to the back passenger side.