Originally Posted by CruiseControl
While getting all neurotic about my ignition system I sported for a new set of Spark Plug Wires, since the manufacturer of my distributor said that a bad spark plug wire could have caused the coil to burn out. While its a bit late to ask for advice in choosing ignition wires, installation tips would be a help. Has anyone ever used conductance jelly at the contact points of ignition wires? would the jelly get to hot and burn up, or would it help lower the capacitance of the entire circuit?
The jelly stuff is silicone grease, AKA dielectric grease. It's purpose in the ignition system is to protect the wire/plug contacts from contaminants by creating a better seal between the porcelain and the wire boot. It also helps protect the boot from dry rotting and cracking, which could also allow contaminants to reach the contacts and corrode them. Most new spark plug wire sets come with either a small tube of dielectric grease that you apply yourself or the grease is already in the plug boots. If it's not in there, you should get some and use it because it can help the plugs and wires last much longer and prevent ignition-related problems. Without it, if the contacts get corroded, you could damage a wire trying to remove it and then you'd have to replace what was probably a perfectly good wire. I would consider it a necessity unless your car's manual specifically says not to use it, but I've never heard of one that did. The same kind of grease is also sometimes used in light sockets in your car that could potentially be exposed to water, and in other places like trailer light hookups. It keeps those contacts clean and dry in the same way.