2000 Durango, 4.7L, 122k. I'm getting a click from the front of the engine compartment on cold starts. Under 30 F only. Installed a rebuilt AC compressor over the summer, but I don't think that's the culprit. Seems to be one of the pulleys the serpentine belt uses. First time having an issue like this. Goes away with some heat/time. Doesn't seem like a huge deal at this point, but I always feel better when my car starts and it doesn't make unusual noises. What am I hearing?