This is my first 5.4 it is a 99 F150 how many miles does everybody run on a set of plugs.
I have heard the horror stories of the plugs blowing out is this caused by a botched plug change or does it just seem to happen.

 

You will notice a difference in idle and performance anytime after 60k. The factory says change at 100k.

 

It's caused by a lack of threads in the aluminum head AND by botched plug changes. You should get at least 100k out of a set of plugs in these trucks. When you change them, USE MOTORCRAFT PLUGS. And then, above all else, torque them properly. If you just tighten them down good, you're guaranteeing a plug blow out.

Gap: 0.052-0.056 in (1.32-1.42 mm)
Torque: 13 ft lbs or 156 inch lbs (18 Nm)

Here is the TSB about the blow outs:
TSB 07-15-2

08/06/07
5.4L 2V AND 6.8L 2V MODULAR ENGINE SPARK
PLUG THREAD OUT OF WARRANTY REPAIR
PROCEDURE FOR ALUMINUM HEADS

FORD:
1997-2000 F-250 Light Duty
1997-2003 F-150
1997-2004 Expedition
1997-2007 E-Series
1998-2004 F-53 Motorhome Chassis,
F-Super Duty
2001-2005 Excursion

LINCOLN:
1998-1999 Navigator

ISSUE
Various 1997-2007 vehicles with a 5.4L 2V, or 6.8L 2V engine with stripped or missing spark plug port threads in modular engine aluminum heads. Ford Motor Company now authorizes LOCK-N-STITCH aluminum inserts and tool kit.

ACTION
Follow the procedure included in the tool kit for using the tools and inserts. Tool kits and inserts can be ordered from Rotunda by calling 1-800-Rotunda (768-8632). Choose option two (2), number 302-00001.

NOTE FORD MOTOR COMPANY HAS DETERMINED THAT REPAIRS MADE WITH THESE ALUMINUM INSERTS AND LOCK-N-STITCH TOOLS DO NOT AFFECT THE HEAT TRANSFER FUNCTION BETWEEN THE SPARK PLUG AND THE CYLINDER HEAD.

NOTE THIS PROCEDURE IS NOT AUTHORIZED FOR WARRANTY REPAIRS AND IS THE ONLY FORD AUTHORIZED PROCEDURE FOR SPARK PLUG THREAD REPAIRS.

WARRANTY STATUS: Information Only - Not Warrantable

 

Over a half-million miles on my modulars(pretty close to a million actually). NEVER torqued or attempted to use a torque wrench on the plugs. Plugs changed every 50-60K miles. NEVER a single issue with a plug or the threads. Attempting to torque plugs in a cramped engine compartment with poor visibility and bad angles is a certainty of thread damage and a failure at a later date.
JL

 

The problem is more prominent on the 5.4L

 

Which makes absolutely no sense. The heads used on the 5.4L trucks are IDENTICAL IN EVERY WAY to the '99-'00 Mustang 4.6L heads,and the '01-up F150 4.6L heads.
JL

 

That may be true, but read the TSB, and then do a search on the forums....

When I did my plugs, I used an inch pounds torque wrench that's not much bigger than a regular 3/8 drive wrench. It's not the easiest job, but it's doable...

 

We've got a fleet of Fords here. Several have the 2V 5.4L in them. Every one of them has had then plugs changed at 50-60K miles, just like my personal vehicles. None of them has ever had a torque wrench on the plugs. None of them has ever had a plug thread failure either. It's not some magical 5.4L problem, nor is it a "not using a torque wrench:" problem. It's an installer issue,and lack of proper maintenance.
JL

 

I was just quoted $560 for a new set of plugs. They said they're $28 a plug because they're the 100k mile Irridium plugs. Can't I just use the Autolite Double Platinum plugs from Autozone? Will this cause a huge issue?

 

I take it you got prices to have the plugs changed on your 01' Expedition? Either way $560 is highway robbery. It is a 2 hour at the very most job.(unless they run into stripped threads) I do a plug change on a 4.6l/5.4l in around an hour, V10s take a little longer.

If so Rockauto has far better prices for plugs. I don't know what engine you have so I can't really post links to the correct plugs. The Motorcraft Single Platinums run around $2.50 each. The Autolite XP series Iridium runs around $4.50 each. I use the Motorcraft single platinums exclusively and change them every 50k miles. Next plug change I am going to try the Iridiums to see if they make a difference. The plug that your engine came with from the factory are Motorcraft Single Platinum plugs.

RockAuto Auto Parts

 

If you want to throw some quick plugs in because you don't intend to keep the vehicle long, the stock Motorcraft plugs are fine.

If you want to keep your truck a while and want a one piece plug that will not break apart in the heads when changed, you'll want the Champion double platinums.

ChampionSparkplugs.com - Application Search Results

The Motorcraft plugs tend to break apart when removing them and some shops charge extra if they break off and they often do.

 

I changed my plugs at 82k due to a misfire. Turned out there was water in the boot on one of the COPs. The plugs looked real nice. Gap was wideer than spec for obvious reasons but there was plenty of electrode left. I changed all 8 and noticed no difference in the the way the truck ran. I could have made it to 100k on those plugs for sure. I took the time to torque the new set to the new Ford spec. Regardless of any one persons experience, these motors have a well documented history if spitting plugs if the orignal 13 Ft/lbs with anti-sieze spec is followed.

 

I changed my plugs this weekend and check engine light came on again. The plugs were due, I went with the Autolite double platinums. I'm taking the truck in today as I have a month left on the warranty. I'm guessing it is a bad coil pack as this has happened twice before. The plugs are a pain to get to, at least the back ones, bit with some patience and research you can do it and save a bunch of money.

 

Absolutely false on 2V engines, plugs do not break apart on them Motorcraft/Autolite are just fine.

 

Just found out it's my ignition coil. Thankfully its under warranty.