While re-tensioning the timing belt, I popped the coil wire off (the one that goes to the distributor cap) and it's full of corrosion. It looks like a really bad battery terminal. What would cause this? Can I just clean it out really good and go on or do I need to replace the coil, wire or both? They're both only a year old.

TIA!

 

I would clean it out .... then check the resistance of the coil wire, the carbon button contact to the rotor, and cap contacts, .... on to wire(s) & plug(s) if indicated. Often, one issue like this can be linked to a few other nasties. The good side is that a good cleaning frequently works without replacing items.

 

A little dielectric grease in there shouldn't hurt either...

 

That dab of dielectric grease will do wonders, applied inside the boot. Keeps the car-wash water out of the coil cap.

 

The coil boots are often missing, mine certainly are.