Hey guys,
Thank you for the response. All the belts seem to check out OK... they are all between 9 months and a year old, with less than 15K mile on them. A few other details. I replaced the A/C idler pulley with a GATES pulley and Gates belt in the Spring, because I was getting a "whirring" sound during humid or wet weather. This fixed the whirring sound, but I still get some quick belt chirp during wet weather on cold startup only. The water pump and timing belt were down 30K miles ago, in May 2012. I installed as part of a kit -- believe it was Mitsobushi.
A few other details:
1. This most recent sound started when the weather got extremely cold, and changes with the RPM of the motor only. It happened on a warm engine at first, and then happened again when the engine was cold. It first lasted for over 20 minutes, and then again for several minutes
2. The sound has changed.. At first it sounded like one of the old fax machines that would ping, followed by static, and then it moved to the whirring sound on the Youtube link. This sound is almost identical to the chirping sound in the following link, between seconds 3 and 10 (not the groaning sound... the higher pitched sound)
https://www.youtube.com/watch?v=NbFek8n5Mac
3. The sound has not happened today, and the temperature is in the mid 20s.
4. On cold mornings, for the past several months, my rig sounds like a turbo - it sort of whistles as RPM's go up and down. This does not go away, but does get a little quieter as the engine warms up. I thought it was a vacuum leak at first, but have not been able to locate any leaks at all.
Any thoughts guys? I am stymied... wondering about the power steering pump, but fluid looks good, and is full... Any thoughts would be most appreciated!
Bryan