Our 2009 vibe emits a high-pitched squealing sound when it starts, but the sound immediately goes away (lasts less than a second). It has been getting steadily worse for several months now. The squealing noise only happens when the engine is cold (has been off for about an hour). I ran a couple of searches here and didn't find any threads addressing the topic, didn't find anything. Dealer says they have no idea, and don't have and can't get a new serpentine belt which is what they think it might be. Any ideas?Thanks in advance.