The 2000 Buick Regal with the 3.8L V-6 engine uses a single serpentine belt to drive the alternator, water pump, power steering pump and air conditioning compressor. It uses an automatic tensioner that compensates for stretching in the belt. This tensioner is marked to show when you should replace the belt. You should also visually check the belt for extreme wear of the ribs on the inside of the belt. If pieces are missing, or you can see cracks running the length of the belt on the outside of the belt, replace the belt regardless of how much stretch it has.
Tools Used: Tools, Paper and pencil, 1/2-inch breaker bar or ratchet, Wrench set
Change Serpentine Belt
Locate the belt routing diagram on the fan shroud. If you cannot find it, draw a routing diagram with paper and pencil so you can get the belt on right.
Locate the automatic tensioner. It is just above the crankshaft pulley on the side of the engine towards the rear of the Regal.