You were told on your last oil change on your Pontiac Grand Prix that your serpentine belt was cracked. They gave you a price for parts and labor and you raised your eyebrows.
But for $20 or under, you can buy the belt yourself and install it yourself and save yourself $45 in labor charges or more. When you get home with the new belt in hand, you pop the hood and look at the belt, realizing it may not be as simple as you thought. But, with proper tools and some patience, you'll have the belt replaced in no time.
Locate the serpentine belt routing diagram. Some Pontiac vehicles may have it located under the hood near the engine displacement sticker. And some may place it on the engine frame rail in the front of the car. If for some reason you do not see one, refer to the link attached and match up your engine size to the diagrams. Another thing you could do is illustrate the routing schematics on paper with a pen or pencil.
Locate the tensioner pulley. It will be labeled on the routing diagram or on the attached link depending on your motor size. Place the 15 millimeter box end wrench on the bolt head located in the center of the tensioner pulley and turn clockwise to release the tension on the drive belt.
Remove the loosened belt from the top alternator pulley and then you will be able to snake the rest of the belt off the other pulleys and remove it. It's a good idea at this point to size the old belt up with the new one to make sure you purchased the correct belt.
Following the routing diagram for your Grand Prix, wrap the new belt around the pulleys starting with the farthest pulley away from the alternator. Since the alternator is the top most accessible pulley, you want to snake the belt around every pulley but that one.
While holding the tension on the belt near the alternator pulley in one hand, use the wrench and to turn the tensioner pulley clockwise again to release the tension and give you just enough room to place the belt around the alternator pulley. You will need to work it on the alternator pulley a little but, but you shouldn't have to force it on. If if was the right sized belt, then it should fit properly and if for some reason it does not, you'll need to inspect the other pulleys to see if the ribs of the belt are lined up properly with the grooves of the pulleys.
Start the engine to test the belt. If you hear any strange noises, shut the car off immediately and inspect the routing diagram again. Otherwise, it should be fine.
