About 4 days ago, Ive got an unusual clicking sound coming from under the hood. It happens when I start the truck, doesnt matter if its been sitting or its been driven around town, the click is there for about 10 seconds or so. I had some time this morning to check it out and found this module doing the clicking. In the pic, its on the firewall with 2 hoses on both sides. From what I can tell, the truck runs normally but the clicking just got me puzzled. Can you guys tell me what that part is and if its normal for the clicking?