Spark plugs blowing out engine.?

Break when try to replace the spark plugs, not blown out.

If the thread is messed up then you will need a helicoil thread repair kit.

http://www.tooltopia.com/helicoil-5334-14.aspx

If snapped.

http://www.tooltopia.com/lisle-65600.aspx?utm_sour...

Ford Triton Blown Spark Plugs

A mechanic may be able to "chase" (re-thread) the spark plug hole. If this is not possible, they will probably have to put in a "Cat" insert. This is done by threading the hole oversize and then twisting in the insert, which brings it back to the proper size. It's kind of a major job to put the insert in, or to a lesser degree to chase the threads as you must keep all filings out of the engine. The spark plug coming out was probably caused by an improper installation. Have you gotten a tune-up lately?

Have seen before, sometimes plugs not tight enough, or someone installed cross threaded and stripped threads in head. If loose re-tighten, if stripped special tools to repair and re-thread, or in some cases replace head. Don't own but have worked on.

Pretty common on the 4.6 they make a repair kit to fix this problem as ford knows well about this.

never owned one but have you checked the threads in

the cylinder head also a quick inspection of the plug

threads if this is the problem just get them re taped

hope this was helpful

have seen it more than once and a special tool to use to replace broken plugs don't know if a parts store carries it but the snap on tools and mac tools carry it