07 ford ranger 2.3l D xl 4x2
176K miles

I started the truck up and noticed a clicking/ticking sound when idling. It happens for a few seconds then goes away then comes back for a bit. When you idle up it goes away and when the truck idles back down it starts again and sometimes louder then stops. Also, when the truck gets warm it will slowly stop but start slightly again. Can’t feel any vibrations really when it happens. Any insight or ideas where I should start troubleshooting! This happened after a P0400 code but I changed the EGR valve and it seemed to clear the fault for now.

here is a clip of the sound
Link