blown spark plugs

I have a 2001 F-250. I had a spark blow out of the head and had it helicoiled. Its been about three weeks and seems to be holding up. I was just wondering what caused it. The shop said it was Fords design. I dont know if I believe them. I just graduated Wyotech and the instructors never talked out it happening and I never heard of it happening. Input please.

A very common problem and do not have to drill it out.There is an extracting tool kit out there for removing the rest of the plug.Snap On does not give them away,$300.00 and most parts stores sell them also

He is correct this is a common problem. This is a sample tool.
http://www.autopart.com/TOOLS/TOOLSMAIN/Tool/T_98140.htm
Use search and buy 98144 insert if you want one with all thread.
Basically they use a 3/4 insert which is bored. The full thread with a full thread plug is stronger. They used to use 3/8 thread plugs. The new ones are 3/4 inch thread but can be used in either insert. I would use a 3/4 heli coil with a 3/4 length plug with a gasket the same brand and heat range. My heli coil kit says not to use a tapered plug. I have a different mfg. but identical kit. I think it is made by time cert. Don't use this kit on a hole with a heli coil in it. It is a bigger diameter but I don't think the tap will be big enough to do this diameter hole.
They do make oversize inserts available on ebay with a drill and tap this is not cheap.

well i had the shop helicoil it. I was broke its my only vehicle. Plus I didnt no if it was like a regular helicoil, so i didnt want to mess up and get some shavings in the cylinder. I have another question. Who well does the helicoil work?

My heli coil kit uses a tap with a reamer on the end just like the picture on the link. If it was put in correctly it will last as least as long as the plug. They put greese on the tap and should vacuum the hole after tapping. In the Ford
Crown Vic forum way2old has some police cars with 50,000 after installing an insert. If you use a double platinum 100,000 plug it should last until you sell the truck if done correctly. The problem is changing the plug will the insert come out. If the wrong length insert or heli coil is used the flame is getting between the plug and the head. This is the problem area.
If worried ask your mechanic what he did?
Go to http://www.ebay.com/ search heli coil and spark plug kit.
You can google triton spark plug kits. Like I said you can buy an over size insert and install kit on ebay. You did what you could afford hopefully you got a good job. The heli coil is stainless and will come with an easy out. The problem is the hole depth.

oh ok sounds good. thanks for the help. I was just really worried about it. Whats the possibility of using red locktight on the outside of the insert to "glue" it in? Thanks again for the advice.

My insert kit mfg. says use high temperature silicon sealant red. I would just leave your insert alone. Apparently you are going to get a job at a Ford garage. Once you make friends at the shop one of them will let you borrow a tool if you have a problem.
I personally don't like heli coils but use them only if something else doesn't work or fit. Some mechanics like them and use them all the time.
On this type of job a problem can occur and if you don't have the proper tools to repair it, could cost you money you won't have until established in your new career as a Ford mechanic.
Good Luck

Well I have a job at a tractor dealership right now and I am starting to get a pretty good selection of tools. I do not no if I want to be a ford mechanic, but I am still looking for a mechanic job somewhere here in Northern Colorado. Everywhere I have been so far says they are full. The even have the lube techs position filled. But thanks for the input. Its not only helping me on my own vehicle but is helping with my knowledge for my career.

I dont recommend using the loctite on the inserts. The High Temp silicone that rhandwor mentioned is the best thing to use on spark plug inserts or helicoils. Combustion chamber temps are hot enuff to melt the loctite, thats how you get it to turn loose when you want it to, by heating it. The silicone will seal and hold the insert well enuff to keep it from coming out when you change plugs but the heat wont damage it. Always use a hi temp anti seize compound when you install the plugs.

i had a 97 ford expedition, i blew 2 spark plugs out of the passenger side cylinder head, had both helicoiled to the tune of 750$$ total, did a bit of research, seems it's a ford manufacturing issue as well as installation, the plug must be torqued properly when installed ( aluminum heads on the 5.4 triton )
my best solution was to trade it off for a chevy! i also lost 6 coil packs at 75$$ each, the motor itself is rock solid, but the stuff attached to it........
good luck!
Rick, Ore