I have a 1997 Ford F150 5.4L that I bought new. It is time to replace the spark plugs and I have herd horror stories about this and read on the Internet that after you replace the plugs some of them will blow out of the hole because their is only a few threads cast into the aluminum head???? I need advice!!!! Has anyone had this happen to them or herd of it?? Any ways to avoid it when replacing plugs any and all comments welcome...(except the Ford bashing comments) Or is it best to just trade the truck off?? Prob is I love the truck it has treated me well... Help please....
I'll trow in my $.02 since I'm fairly familiar with it...
Like the others said, its somewhat common and the dealers will have mixed results with it. I would sooner trust a good dealer tech with my tune up than any independant.. Dealers can be hit or miss too, you have a 50/50 chance of getting a good tech, but I think those are better odds..(there are good independant techs out there too, but they are less familiar with the engine)..
I deal with MANY dealer techs on a regular basis. Every time the topic comes up, its an overwhelming agreement that the plugs were previously changed outside the dealer(usually with aftermarket plugs, they arent the problem, but a dealer didnt put them in).. Although there are only 3 threads in the head, the issue seems to stem more from improper torquing of the plug. Because its an alluminum head, most people are intimidated by tightening them properly and leave them loose. With a loose plug, like a loose bolt, the likelyhood that it will blow out or loosen more is greatly increased.. I know of VERY FEW dealer techs who have ever had a plug they put in, blow out..
If by some chance they do blow out, it sucks.. The "heli coil" idea works for some guys, but not with a heli coil.. A
Time-Sert is the way to go(IMO). They work really well, again, it relies on a good tech to do the job.. It should never need to be done again.. My buddy charges $500(dealer rate to the customer)plus parts for the first hole. I'm not sure what he charges to do multiples on the same engine.
Personally, I would take the 100k m tune up to heart and not short change these.
As for the newer ones('05 and up). This is a TOTALLY different situation.. It would be a smart thing to again let the dealer do it.. My reccomendation for a pre tune up "PREP" would be a little water injection to loosen any carbon in the combustion chamber that will "stick" the plug in the head. The dealer has a special procedure to use as well as a special tool to remove the broken plug if needed..
Hope that helps some..