I have a 2021 RAM 1500 with just over 20k miles. Hemi 5.7 etorque. A couple weeks ago (during some cold weather) the truck suddenly started making loud ticking noises while at temperature. It sounded kinda like a sewing machine in that the ticking frequency revved up (and down) with the engine RPMs. I got home, checked oil level which was fine, and turned the truck on and off a few times--noise was still present. So I left the truck parked in my driveway until I could get an appointment at the dealer about 1.5 weeks later. The truck made the noise again on the way to the dealer. However, the dealer calls me after 2 days of driving it around and they claim they haven't heard any unusual sounds. They said the exhaust manifold and bolts check out--no issue there. I request they keep it a 3rd day and try again. Still nothing. I pick the truck up and it indeed sounds fine...until I get home and turn the truck on and off. The noise shows right back up. I've been driving it several days since and sometimes it makes the noise--sometimes it does not. I'll try to post a couple YouTube videos...in one of the videos I took you can actually hear the ticking sound go away around the 2nd engine rev. When it does make the noise it has usually been while idling after reaching temps. Or restarting the truck after reaching operating temp. I'm not sure my next steps at this point. Has anyone else had similar intermittent ticking ("sewing machine") sound issue?