Rattle from alternator?

[Flyingfifer]

So over the last year and a bit the Coupe hasnt been very far (4k miles in 12 months vs the usual 13k) as such I had a battery death issue having left the car too long, its now getting a blast at least once a week to keep it charged but I noticed a significant rattle (sounds like something very loose) from what sounds to be the alternator, looking at it there isnt anything obvious with the belts all looking fine and the battery is being charged still when running the car. The issue sounds to be worse when the car is cold but is still somewhat present when up to temp.

New alternator?

2006 Coupe with 101k miles fully serviced religiously

 

[colb]

First thing is take the belt off and run the car to see if the noise dissappears, if its gone then spin by hand the alternator pully and all of the belt idlers to see if they are running rough and causing the noise. Any found feeling rough will need replacement. If your lucky it will be an idler bearing if not then the wallet will take a hit for an alternator. Rebuilders are few and far between these days who would simply replace the bearings in a unit.

 

[Old-Duckman]

I had the sound of a rattling a can full of rock in my Z3, a friend of mine used one of those mechanic's stethoscope to locate the source. They are reasonably priced and can be invaluable for such things.

Mine ended up being the water pump and I replaced the belt tensioner and idle pulley while I was at it.