meyeste Posted March 13, 2006 Share Posted March 13, 2006 I am taking my '99 F-150 4X4 Lariat in to the dealer to have the spark plugs & wires replaced now that i am 7k shy of 100,000 miles. I recall in these forums there was a note about a replacement plug that has taller threads to help prevent the plugs from going through the hood, does anyone know what that part number is? I asked my dealer about the existence of a replacement plug with taller threads and they had never heard of it. If someone knows of the plug I am thinking of, I'd appreciate the information. I am thinking the part number was the same as the original but has 'g' vs an 'n' or something like that. Quote Link to comment Share on other sites More sharing options...
Ron W. Posted March 13, 2006 Share Posted March 13, 2006 Yes get them changed, at 100k miles you've been lucky i don't care how many miles Ford says they will last. Yes the AWSF prefix plugs have been replaced by a AGSF prefix part number so instead of about 3/8" of thread you've got about 5/8" of thread. Also it will cost you more (for parts, should not be any extra labor) but have the C.O.P. (coil on plug) boots changed at the same time. These plugs are not fun to change and have torqe specs. no more just tighten them up. Have a PRO do it. Quote Link to comment Share on other sites More sharing options...
J-150 Posted March 13, 2006 Share Posted March 13, 2006 I asked my dealer about the existence of a replacement plug with taller threads and they had never heard of it. Stay away from that dealer!!!!! Go to a dealer that is aware of the situation and will put the correct plugs on the truck. Good luck! Quote Link to comment Share on other sites More sharing options...
meyeste Posted March 16, 2006 Author Share Posted March 16, 2006 Well I had the spark plugs replaced after confirming they were using the "g" plug. I also had a bad coil which was why the engine had started vibrating oddly, I also had them change the fuel filter. Bill came to $611, I have to change the plugs on my car soon also, luckily I can do these myself. Quote Link to comment Share on other sites More sharing options...
cheri/ck Posted March 16, 2006 Share Posted March 16, 2006 Yes get them changed, at 100k miles you've been lucky i don't care how many miles Ford says they will last. Yes the AWSF prefix plugs have been replaced by a AGSF prefix part number so instead of about 3/8" of thread you've got about 5/8" of thread. Also it will cost you more (for parts, should not be any extra labor) but have the C.O.P. (coil on plug) boots changed at the same time. These plugs are not fun to change and have torqe specs. no more just tighten them up. Have a PRO do it. I am also also about to have the plugs changed for the first time in our 1999 F-150 5.4 and just like everyone else that pays attention to these things, can't help but be nervous about it. The dealer is a high volume dealer with an excellent service department. The truck has been 100% serviced by this dealer since new. I realize that it is wise to have the boots replaced on the coil packs. Is there any other way to spend more and hopefully keep this engine running reliably for a long time? It will have about 85,000 miles on it at the time of the plug change and I want to do whatever I can to keep the engine going strong without a major repair down the road. For one thing, would it be advisable to pay to have the torque of the replaced plugs checked a few months after having the plugs changed? I do not like the new F-150 and this 1999 is in beautiful condition and has been mechanically perfect. It is running fine, but approaching seven years of age and I think that is long enough to leave spark plugs in a questionable aluminum head. I'll be talking with the service department about my concerns, but appreciate any other advice. Quote Link to comment Share on other sites More sharing options...
Hosh Posted March 16, 2006 Share Posted March 16, 2006 I have a 2002 F150 Lariat with 109000 Km on it. I went and got the printout of what the dealership does for there 100 000 Km tune up, and for spark plugs it said, OP Code 100P,replace platinum sparkplugs, Part#SP479. Would this be the proper sparkplug(AGS prefix) :shrug: My other question is does this spark plug problem apply to the 2002's? Quote Link to comment Share on other sites More sharing options...
cheri/ck Posted March 17, 2006 Share Posted March 17, 2006 I have a 2002 F150 Lariat with 109000 Km on it. I went and got the printout of what the dealership does for there 100 000 Km tune up, and for spark plugs it said, OP Code 100P,replace platinum sparkplugs, Part#SP479. Would this be the proper sparkplug(AGS prefix) :shrug: My other question is does this spark plug problem apply to the 2002's? Can't answer the plug part number question, but I have read everything that I can find about the blow-out problem. Ford apparently redesigned the heads with more threads for the 2003 model year. However, it appears that early 2003 models still have the old heads as Ford used up their supply of these heads before starting with the newer design. Your 2002 should have the old design. There is some debate as to whether or not the longer plugs matter since there are only so many threads in the head design. Guess the longer plug would take longer to work out of the plug hole, but if a plug is coming loose - it would still have to be caught in time before damaging the threads in the head. On the plus side, our dealer changed out the plugs on our other F-150 (2001) a year and 25,000 miles ago. Have had no problems so far. Quote Link to comment Share on other sites More sharing options...
Ron W. Posted March 17, 2006 Share Posted March 17, 2006 (edited) HOSH the SP479 is indeed the AGSF prefix -- Cheri/ck i own a 97 F150 5.4L with just over 134k miles on it, no engine problems (noisy as hell on a cold morning startup- normal). My advise is keep the filters and fluid clean ( i change my oil and filter every 2K miles.) Edited March 17, 2006 by Ron W. Quote Link to comment Share on other sites More sharing options...
Hosh Posted March 17, 2006 Share Posted March 17, 2006 Thanks for the info Cherri and Ron, much appreciated Quote Link to comment Share on other sites More sharing options...
Ron W. Posted March 19, 2006 Share Posted March 19, 2006 A good place for mechanical advise http://www.flatratetech.com/forums/index.php?showforum=13 Quote Link to comment Share on other sites More sharing options...
06GT4RAD Posted April 7, 2006 Share Posted April 7, 2006 Yes get them changed, at 100k miles you've been lucky i don't care how many miles Ford says they will last. Yes the AWSF prefix plugs have been replaced by a AGSF prefix part number so instead of about 3/8" of thread you've got about 5/8" of thread. Also it will cost you more (for parts, should not be any extra labor) but have the C.O.P. (coil on plug) boots changed at the same time. These plugs are not fun to change and have torqe specs. no more just tighten them up. Have a PRO do it. I agree with Ron !00% DO NOT let these trucks go 100k before changing the spark plugs. I have seen so many issue from plusg not coming out, not able to get a spark plug socket onto the plug do to so much dirt down in the plug hole, and also have pulled plugs out that literally had nothing left to them and was amazed the truck ran. My personal suggestion is 45k for plug changes. And yes go to the longer threaded plug. Richard Quote Link to comment Share on other sites More sharing options...
F250 Posted April 22, 2006 Share Posted April 22, 2006 The problem isn't the number of threads on the spark plug it's the number of threads that were in the early cylinder heads. If the head has only 5 threads tapped in it then that's all there is to secure the plug, installing plugs with threads all the way up to the combustion seal (the angled part above the threads and below the hex) only means those threads are wasted and do nothing to secure the plug. The phase in for the new heads was 2003. Quote Link to comment Share on other sites More sharing options...
meyeste Posted May 1, 2006 Author Share Posted May 1, 2006 Can't answer the plug part number question, but I have read everything that I can find about the blow-out problem. Ford apparently redesigned the heads with more threads for the 2003 model year. However, it appears that early 2003 models still have the old heads as Ford used up their supply of these heads before starting with the newer design. Your 2002 should have the old design. There is some debate as to whether or not the longer plugs matter since there are only so many threads in the head design. Guess the longer plug would take longer to work out of the plug hole, but if a plug is coming loose - it would still have to be caught in time before damaging the threads in the head. On the plus side, our dealer changed out the plugs on our other F-150 (2001) a year and 25,000 miles ago. Have had no problems so far. It is my understanding that the new spark plugs have taller threads, and so they engage more of the 6 existing threads cut into the aluminum heads. The old plugs that came out of my truck didn't look that bad frankly. One other note, I have also heard that the longer you wait to remove the plugs, the more likely they will take the threads of the heads with them when they come out. By the way when mine were done I also had to have a coil replaced, (complete shutdown of cylinder # 4) this is what actually brought me in to the dealer. '99 SuperCab Lariat Quote Link to comment Share on other sites More sharing options...
cheri/ck Posted May 3, 2006 Share Posted May 3, 2006 It is my understanding that the new spark plugs have taller threads, and so they engage more of the 6 existing threads cut into the aluminum heads. The old plugs that came out of my truck didn't look that bad frankly.One other note, I have also heard that the longer you wait to remove the plugs, the more likely they will take the threads of the heads with them when they come out. By the way when mine were done I also had to have a coil replaced, (complete shutdown of cylinder # 4) this is what actually brought me in to the dealer. '99 SuperCab Lariat Just had mine changed too on our 1999 F-150 5.4 and everything went fine as far as I know. Also had the coil boots replaced at the same time. It had about 83,000 miles on it, but I was leary of waiting any longer and got no argument from my dealer. The truck was running fine when I took it in however it is really running good after the plugs were changed. Don't remember it ever idling so smoothly. No problem with the coils either. Glad to have that behind me and I think my dealer did a very good job on it. Even cleaned the engine up nicely and polished the fuel rails. Quote Link to comment Share on other sites More sharing options...
kenp77 Posted May 3, 2006 Share Posted May 3, 2006 Just had mine changed too on our 1999 F-150 5.4 and everything went fine as far as I know. Also had the coil boots replaced at the same time. It had about 83,000 miles on it, but I was leary of waiting any longer and got no argument from my dealer. The truck was running fine when I took it in however it is really running good after the plugs were changed. Don't remember it ever idling so smoothly. No problem with the coils either. Glad to have that behind me and I think my dealer did a very good job on it. Even cleaned the engine up nicely and polished the fuel rails. What did it cost if I may ask?? Thanx Quote Link to comment Share on other sites More sharing options...
cheri/ck Posted May 3, 2006 Share Posted May 3, 2006 What did it cost if I may ask?? Thanx It wasn't cheap. With taxes and assorted fees, around $400. The boots for the coil packs are pricey - I'm not looking at the invoice, but I think they charged like $12 each for those times 8 was about $100 of the price. I don't care and glad to have it done. The mechanic charged nearly 3 hours of work on the truck. And, there is every indication that the work was done well and not rushed. Money well spent on what has been a 100% reliable vehicle up to this point. Hoping to keep this truck running well for several more years so this seemed like a minor investment for what can be a lot of expensive problems if not done properly and carefully. Quote Link to comment Share on other sites More sharing options...
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