1999 Dodge Dakota Click, crack, click, crack.

Hello

My 99 Dakota R/T currently has 125K on the odo and runs with full power. In the past 3 months I have done the following: New battery, dcap, rotor, plugs, wires, dcap module, coil, rear abs speed sensor, etc, as well as an oil change 3 weeks ago.

In the past 3 weeks, I have noticed something odd as the engine warms up now that our mornings are somewhat cold. The truck starts up perfectly fine but as it runs, you can hear an odd sound eminating from the alternator/coil area. It doesn't sound like metal on metal but more of like a crackling sound. After a few minutes of warming up, the sound goes away. As I said, the truck runs great. It has full power and is quiet (except the magnaflow exhaust) and if you start the truck later on in the day, you'd never know it has a slight out of place sound early in the am. Clogged injector, bad plug, etc, any ideas?

Thanks,

JCU