'96 Accord: When I switch on the A/C I get a loud "whirring" noise...so loud it's very noticeable from quite a distance from the car. I can't quite pinpoint the source but air is plenty cold, so compressor seems to be working OK. Would this likely be a bearing in the compressor, an idler bearing that gets noisy under load, or a developing mechanical problem inside the compressor itself? Is any one of these more prone to failure on this model?