if there is no problem then why did ford change the design of the threads? when new engines come out they have problems that sometimes aren't figured out until years of use. when those problems pop up, they make design changes to fix the problem. remember when the 97-98 f150 supercabs failed so miserably in the crash tests that ford had to totally redesign them so they wouldn't crumple on impact? not every single f150 experienced it, but many did. that is a design flaw.

it just amazes me at how so many ford owners justify or pretend like problems don't exist. if it was the hemi having plugs blow out at the rate the 5.4 does then there would be countless threads on how sorry the hemi is, how dodge can't build a truck worth a crap, etc. it's like the 6.4 guys saying they are glad that they have to remove the cab to do any work other than an oil change. really? would they be praising that design if it was the silverado that had to have the cab removed to change a 10 cent turbo o-ring? i don't know about you, but i prefer to raise the hood to do work on my trucks, not the cab. i'll never own anything but a ford, but that won't stop me from admitting that they have came out with some pretty stupid designs on some of their newer stuff.

 

We've got literally MILLIONS of MILES driven on my personal vehicles and out work trucks,and NOT A SINGLE ONE has had a plug problem. The work fleet is mostly all the old "problematic short-thread" 2V's too.
I stick by what I'm saying-period.
JL

 

you may have some of the 95% that dont have problems. i hope mine doesnt have any problems either. its not like 50% of them are going to have plugs blow out or some crazy number like that.

i read somewhere a while back that ford does a recall on anything that goes wrong on more than 5% of their vehicles. whether thats accurate or not, i dont know. the 5.4 was never recalled for the plugs, so it has to happen on less than 5%. lets just say 500,000 triton engines were sold in 2000. that means at most 25,000 of them could blow a plug and it not be recalled. and thats just from one year. i would be willing to bet there havent been 25,000 spark plugs blown out of all of fords engines from 1965-1995 combined. you may never experience that problem, but to me, thats still a design flaw.

 

I don't think I said that they haven't been changed at all. They very well could have been at some time before I bought it.

I haven't touched them in 76K miles...or since I bought the truck.

I would also like to know sir, that if you don't torque the plugs down to the specified torque that Ford recommends for these engines, how can you tell if you are getting them tight enough?

I change plugs in aluminum head engines on motorcycles and atvs only they have more than a few threads in the holes and I just snug them up a little, crushing the gasket.

 

it's amusing to read the different responses. My truck's a 99 f150, 5.4v8, with a lot of engine mods, its mileage is 265,000km, one plug blew just after i bought it, and happened twice, weeks apart. That was 5 years ago, plug was motorcraft. No problems since then, and as one of you mentioned, I don't touch them. Regardless of what you all think, don't forget one thing and that it's an opinion. None of us can say without a doubt that its an installation problem etc. I was told by a service advisor, about how they lift the cab off to do the heads, and that's there procedure. my guys removed the head to put the helicoil in, and even then was telling me about the issue with these engines and the lack of a proper thread depth. I do believe it's an issue, as it also happens to the cars as well, and even other manufacturers, it just happens to ford trucks more often, and that's my opinion. I do most of the maintenance myself and i always did on my other vehicles. Up here its costs a bit more to repair the problem. But at this point there isn't anything else i really want to do to my truck, as i'd have to replace the engine, so i can have a supercharger(procharger) installed. So i'm moving up to an 05. So that's my opinion. In the end we all believe want we want, regardless.

 

Sometimes you have to wonder if manufacturers do testing to see how long something will last so it will fail soon after the warranty expires. These Ford spark plugs and Ford plastic planetary gears in the power window motors on Lincoln/Ford/Mercury vehicles are a few good examples. Could this be by accident, coincidence or by design? Who makes a head with only 3 spark plug threads and expects it to be used on a daily basis towing a trailer for hundreds of thousands of miles without failure? Who makes plastic planetaries on a power window motor? Does an engineer come up with an idea like this or is he "TOLD" to design it with a certain life expectancy? When you go into a dealership do you think to ask if the heads have more than 3 spark plug threads or if the power windows use plastic planetaries? Of course not. I seriously doubt this all happened without the knowledge of upper management. Some people DO overtorque fasteners and spark plugs. This can contribute to early thread failure especially if you only have 3 threads to start with. Plastic planetaries dry out and crumble into small pieces after a few years

 

Hey JL,

Always appreciated your input and advice but could you clarify a couple questions I have based off this quote? First, take a backyard mechanic like me who likes turning a wrench and working on his own vehicle but does it occasionally. Because Ford has the "recommendation" of 7 to 15 ft lbs of torque per plug and all them paranoia surrounding these plugs ejecting, what do you say for those of us who like to be absolutely sure the plugs are in spec and fear not having the reassurance of the torque wrench reading?

Before answering, yes it is damn near impossible to accurately torque the plugs die to all the extensions. The only plugs that I remember being 100% sure about were numbers 1 & 4. However, I don't trust myself enough to simply tighten the plugs by hand. I feel much more confident knowing I used a torque wrench...and I think a lot of other members on here would feel the same way I do.

With all of this said, when I did my plugs I used lots of anti-seize, took my time and using extensions and swivels (especially on plugs 3 & 7), torqued my plugs all to 12 ft lbs. And then I re-checked all the plugs again after that. Do you think I should go back and double check all the plugs by hand? When I did torqued them, all of the plugs felt like I just "snugged" them in place. Not tight nor loose. Lastly, do you ever recommend occasionally pulling out the COPs and checking the plugs to make sure they have not loosened up?

Thanks JL
Tom

 

You get a feel for it over time. I tighten by hand to a specific "feedback" feeling.
Checking them periodically will help prevent the "blowout" issue if you're uncertain on how tight is tight enough,or if you do alot of driving with ping/spark knock present. Too loose is just as bad as too tight, and driving with pinging and spark knock present can "rattle" them loose.
JL

 

you can get really close with a torque wrench even with extensions on it. you just have to "calibrate" the wrench with the extensions on it. take your wrench and torque a bolt down to 12 ft lbs without using an extension. take the extension you are going to be using and put it on the torque wrench. dial your wrench down to about 8 ft lbs and test it on the bolt you just tightened. work your way up in 1 ft intervals until you see the bolt move just a little before it clicks. that will put you 1 ft lb over the 12 ft lbs that you want. dial it back 1 ft lb and that will put you where you need to be. your wrench may read 15 ft lbs but it will actually be 12.

 

97expyguy-

also, when torquing something in the lower range like that i would recommend using an inch lb wrench instead of a foot lb. its more accurate, the click is more pronounced and its less prone to operator error.

 

Not with a universal joint on it.
JL

 

That's not a bad idea as I never calibrated my wrench when during installation. I simply put the wrench on 12 and worked slowly. I'll look into rigging up one of my old spark plugs I pulled and play around with the torque adjustments. I guess at this point since I did mine at 12 ft lbs, the worst I could be at is 8 or 9 ft lbs on the back plugs. The only thing I hate about the job is that fuel rail...

 

if he calibrates it with the universal on it then it will be. it wont be exact, but it will be close. either way, for a back yard mechanic that probably doesnt have much experience torquing bolts, it will be much closer than just guessing at it by feel. and how many does he need a universal joint on? 2? i would rather 6 be exact and 2 somewhat close than to have all 8 be all over the place.

 

Nothing in your last few posts is anything near "calibrating". It's more like a hackjob attempt at trying to get a repeatable result.A universal requires different torque to turn based on where the centerline of the universal's joint.
it is not repeatable,nor is it accurate.
JL

 

ok, so telling him a perfectly good way to get 6 of them exact and 2 close is a hackjob attempt but telling him to just randomly tighten all 8 by feel is more accurate?

and yes, the universal does require different torque based on the centerline.....but do you not think he can recreate that centerline? if its bent at a 45 degree angle to put the plug in, then just bend it at a 45 degree angle when adjusting it on the bolt with the known torque. go home and try it some time. you would be surprised at how you get within a lb or 2 every time. i doubt he could get that close by feel.