Originally Posted by imidazol97

I've noticed this on my 98, and occasionally on my 03 I feel a chugging as if the high load might cause the belt to slip at idle. The 03 has a belt that doesn't seem rubbery like the original and might not give a squeak as it slips but might do it quietly due to the texture.

I was wondering if age causes the idler tensioner to lose pressure against the belt. That means under high load with the alternator working hard to produce amperage, the belt may be slipping.

I'd try turning everything on right after the car has sat and then spraying water onto the belt in front of the alternator to see if you get a slip at idle.