Most (if not all) of the blown plugs are the threads ripping from the head. Over torquing could strip the (I think) 4 threads from the head and make you need a helicoil. The 7-14 ftlbs is what I've always heard and that sounds right. My old 302 only required 23 ftlbs for its intake bolts. Why would a spark plug need more tq than that?

 

These heads don't strip till 80 ft/lbs or more. 28-32 is the new recommended spec. Alldata and Chiltons uses the old spec that Ford still uses and still gets blow outs. Please be careful using old data that is known to cause issues. I've only ever heard of one blowout out of thousands using the new spec.

 

Agreed,

17 ft lbs is way too loose to lock just a few threads up with never seize and expect them to stay put through heating/cooling cycles, vibration and pressure... If there was more thread contact (thus creating more surface area to lock up against) like most heads, it would be fine but there isn't... It is proven all over the web, if you use the old specs, you are entered into the raffle for a blow out and hopefully you don't win... I have a friend that eventually blew out all 8 following Fords specs... Don't ask me why he didn't second guess the torque spec after a couple blow outs, by the time he told me about it he had just heli coiled the last one...

 

Why would the old specs not work? Isn't that what they used when they came from the factory and they worked fine? And if ford still uses the old spec, then what source came out with a new one?

 

They came from the factory blowing out, obviously not working. The blowouts continue to this day. Ford techs, the Ford techs at Blownoutsparkplug.com, and countless users came up with the new spec. Ford never decided to submit and Oasis or TSB (it was brought up and they rejected it), they decided to let customers foot the bill for the blowouts and continue with the old spec.

 

I have found the main cause of plugs cumming loose is oil, grease in the plug sockets so if you clean them up and have bare metal down there before you put them in they will seat and not come loose at the recommended torque of 14 lbs of torque and you won't damage the threads which will cause you more problems in the future. Also, the anti seize on the threads will protect them and allow you to take them out without damage to the threads in the future when you change plugs. If you damage the threads in the two back plug sockets, you cannot install the heli coils because you can't get at them and the only fix is lots of thread locker or lots of money for a new head.

When you started the truck after changing the plugs and it ran rough it was most likely from that same crud in the plug sockets getting down in the cylinders and burning up when you first started your truck.

 

Ford published a TSB 962523 which raised the torque recommendations from 9-20 n-m to 16-20 n-m (12-15 ft-lbs).

 

Otto, I value your opinion and based on multiple posts of yours I have read(specifically the one on the backpressure/your super jumbo-sized /stickied exhaust thread. ). I believe you to be extremely knowledgable on vehicles.

However, though I may be bitting a bullet, when I do eventually change my sparkplugs I plan on using the 14 ft-lbs. of torque. Reason being, is my truck currently has 63,000 miles on it and has passed the recommended 60,000 mile sparkplug change with the plugs torqued to factory standards. They didn't blow early in the game and made it passed(although only by 3,000 miles so far) the point where they should be replaced. For me, this shows that factory specifications worked and I plan on using them. Also, the Chiltons book I'm using was purchased December 2012(copyright 2009). I can't see any way this can be considered outdated information(unless, of course Ford rejected the claim to change torque specs and Chiltons used it).


Anyway, since 14-ft lbs. has worked for 13 years so far. I plan on using what it was made with. If I do blow a plug after the change. I admit I was warned

 

I'm kind've chuckling at this thread now...

I agree with what Harley said earlier here... Although I did break out the torque wrench to set the plugs to what I felt best (30 ft lbs) judging by the research I did just to maybe avoid a potential issue, and I've been fine for over 20k now....

I would much rather just give em a good snug bump by what feels good to me (which would probably leave em around 30ish anyway) than to read this much into this subject...

I have three friends that have had blow outs, one I mentioned earlier (all 8 plugs), 2 had cyl #7 blow out... All were just over 100k when this started to happen, and they maintain by the book... All went with the high end of Fords suggested spec when I talked to them out of concern... And that's just my immediate friends, never mind friends of friends etc (This area is loaded with Ford's)... Like I said earlier it's a raffle or lottery, it won't happen to everyone but from what I've seen/heard, you'd be better off leaving the torque wrench out of the equation and just snuggin em up then to leave these that loose...

But it's your truck, and its not like it's gonna total it when a plug blows out, a quick fix is at hand...

 

Lol alright guys let me shed some light here, why there's conflicting tq specs haha

13-14lbs with anti seize and 24-26 without anti seize...

Hope this helps...