I had a chirping noise at idle that went away when driving, at least I could not hear it while driving. Took the car to the shop and they replaced the serpentine/fan belt. Next morning I started the car and heard all sorts of clacking going on under the hood. Upon inspection, the noise was coming from one of the pulleys - sounded like a bolt was loose and rattling around inside one of the pulley cases. After a few minutes, the noise disappeared. While driving about 2 miles later the noise reappeared for a few seconds then went away again. The mechanic shop could not duplicate the noise and said not to worry about it unless it happens again and all of the time where they could diagnose the problem. I just returned from a business trip, drove my 855T Wagon 1200 miles round trip and she performed flawlessly (well except that the A/C appears to need a recharge). This morning, the noise was back, then went away again and has not resurfaced in 50 miles. Any idea what this gremlin might be? Alternator? A/C Condenser (or is that the compressor?) ? Is this a bearing noise that comes and goes intermittently? Anything I need to check/replace, hard to find since it does not always happen.

Thanx.

Keith