if you need a heil-coil to be put in cylinder 4 does that mean you have a bad cylinder or a stripped spark plug ?
if you need a heil-coil on 1999 Plymouth Breeze
it means that one of the mouting bolts to the head is stripped. The healie coil is a replaced thread after the hole that is stripped is cleaned out by a drill and a new thread starter is made for the coil. When the thread is made in the hole, its made counter clock wise so that the helicoil can be screwed in clock wise
1 more answer , 2 more comments
They probably mean the threaded hole that the spark plug screws into needs to be drilled and a heli-coil insert installed
A stripped thread in the cylinder head. This usually happens if you remove the plugs when the engine is hot. Aluminum damages easily if not cool first. Other the last plug service. dirt got in and got in the threads and damage during removal process later.
ok some dumb service guy wanted me to beleive they was trying to repair the cylinder head with heli-coil, he never told me why they use hel-coil I look it up online though, in what you said sounds right thanks