I have seen some very troubling problems supposedly related to sparkplugs in the Triton engines, 4.6L and 5.4L, where the engine reportedly ejects a plug by stripping out the threads in the head bore!! This is very scary stuff!

Is not the 4.6L engine in the F150 the same 4.6L engine used in the Lincoln TC, Ford Crown Vic (civilian and P71) and Mercury Gran Marquis? None of the owners of those cars have reported such serious plug-retention problems....What gives??

 

As I recall, the 4.6 was not affected. Just the 5.4, would spit plugs and it was for certain years. Something like the 99 thru the 01s or 02s. It's an easy fix with a helicoil.

 

I hope you're right, Bluejay, because the 4.6L in my 97 at 121K is probably due some new plugs....unless the first owner had replaced them.
Replacing plugs in the Triton is difficult enough without the spectre of damaging the plug-bore threads.

 

I had my 99' f250 v10 spit out one plug. We put a helicoil in and its been about 40,000 miles later no problems.

 

Pretty sure all the 2vs were susceptible, just wasn't a very common problem.

 

I hsd my 97 5.4 lose one right after a plug change. I had the plugs changed at the dealer so I blamed them. The ended up fixing it for free..

 

Pretty much all 2v's from 91-03 are affected by this. The problem is not enough threads in the cylinder heads. The higher output the motor the more likely it is to spit the plug. Just ask the lightning guys how many they have had to fix.

On November 12/02 they started production on heads with more threads for the spark plugs. I recently was looking to swap my motor for a newer one with the updated heads. The newest motor I found was assembled on April 1st 2003 and it did NOT have the updated heads.

You likely will not have a problem, make sure to torque to ~20-22ft/lbs. Ford recommends 12-16ft/lbs I use a little more. Do NOT use antisieze. Retorque them about once a year. I have done a ton of research on this issue.

You are more likely to replace BOTH a 10 bolt rear end and 4l60e tranny (very common very weak GM points) before you will have to deal with a blown out spark plug.

 

Very true the 10 bolt and 4L60E both crapped out pretty fast in my Camaro, the 10 bolt was easy to break with stock power. It was not that bad though, just an excuse to throw in some 4.10's and a 4000 stall converter lol. Tranny and rear are holding 430+ hp now with built parts, fingers crossed.

 

Believe me, if the plugs in my 97 4.6L need to be changed, I will bite-the-bullet and have a dealer do the work with its concurrent guarantee to repair if something goes haywire!

Thanks, Mates, for all the good advice.

 

The guys at blownoutsparkplug.com recommend 28-32 ft/lb on the 4 thread heads.

 

I worked for a major gov't trans. agency that used CV police interceptors. They only ever used the 4.6L and they spit plugs (not an everyday occurrence but it did happen now and then)

 

Yep, I've heard the same horror stories from our city, county, and state LEO's about early 2000's CV's doing the same. One guy (friend of mine) even showed off the "pimple" in his hood from an aborted pursuit run on I-8. New head, COPs, fuel rail, new this,that and the other thing; left the hood alone - he calls a battle scar.