Odd idle
 

My engine idles at around 600rpms. Every 20 or 30 seconds I hear a sound like a old school relay clicking over and the rpm jumps to around 900 then settles back to 600rpms. 20 or 30 seconds later it goes again. Anyone else experiencing this or know of a possible reason? Is it something to be concerned about?

If your heating/cooling is on, yes.

Edit: yes it is normal, and no it is not something to be worried about.

Just to be clear ;)

That clears up the confusion. It was cold this morning. Thanks!