My Kia Picanto '2004 with 1.1 engine (I'd mention in the Hyundai Getz, which has the same motor), makes this howling noise when starting the motor after a cold night. The volume of the noise decreases within a few seconds, but it stays noticeable for maybe a minute.
In the past, it made this noise only when it's very cold, like -8°C, but now this happens every morning, though the temperatures are around 0°C.
Any idea what could be the cause of this noise? It's not the belts, since those would sound different, plus I poured some water of them to exclude they make the noise.