Hey I know what a wire in a wire looks like and this was a wire IN a WIRE!!! I crimped the inside wire (using a reduced butt connector) and used heat shrink to protect it. I then used some extra copper wire I had in the house and wrapped the already heat shrunk segment making sure that the outside wires from both ends were connected and then used more heat shrink around that . AGAIN YOU WOULD NOT KNOW THIS WIRE IS A COAX TYPE UNLESS YOU CUT IT!!!! THATS WHY YOU HAVE NEVER SEEN IT BEFORE. I am pretty sure this is the knock sensor wire.

 

Upon further research you are indeed correct...some knock sensors do use a shielded wire. I apologise

http://www.dslreports.com/forum/r239...-wiring-repair

 

It's just shielding though, I don't think leaving an inch or 2 of the splice unshielded would matter.