I have a 2008 1800 with 28K on the clock. Purchased it this spring from a reputable dealer at 24K. At idle it has a noticeable growl in the engine. Experimentation has yielded a belief that it has something to do with the alternator. If I load up the electrical system the growl vanishes immediately. i.e. depress any brake lever; turn on bright headlamp; turn on driving lights---anything that causes the alternator to begin producing current makes the noise go away. Do not hear it at speed but that doesn't mean it is not present. Is not affected by clutch or drive train movement---only adding draw to the electrical system. Have asked a couple of dealer mechanics---not usual. Anyone have any thoughts?