Not like the videos. From the inside it sounds like something is knocking on the firewall (or other surface). It is slow (about once per second). When I get out of the car it sounds like something is clicking back and forth, or opening and closing. It kind of has a suction sound to it. It only lasts 10 - 15 and then slows right before it stops. It is difficult for me to describe as this morning was only the second time it has done it this year. Only seems to happen for the really cold morning start ups. I leave before the sun comes up as well so I couldn't investigate. I guess I'll have to bring a flashlight out with me from now on. Anybody else think my description sounds familiar?