First, let me start by stating that I am a relative newbi to car maintance and these procedures are very simple.
Engine: 3.0L Vulcan
Symptoms: Squealing coming from serpentine belt at a cool startup (i.e. sitting overnight, cool engine). The squealing tends to last about 10-15 mins and dissipates when engine has reached NORMAL operating temperature.
The easiest way is to purchase a serpentine belt removal tool from your local shop (you may rent one as well). The average cost for this tool is $25-30. I opted for the purchase so that I may keep the tool in my trunk for those mishaps in the future... along with a new belt!
15mm 6pt or 12pt socket - comes with the serpentine belt removal tool.
Step 1: Remove the belt!
Place the serpentine belt removal tool with a 15mm socket onto the tensioner pulley bolt and rotate the bolt towards the front of the car (clockwise). This will relieve the tension on the belt and allow you to remove the belt.
Step 2: Inspect the belt.
The belt should not have cracks that run parallel to the grooves. It is okay for the belt to have some minor cracking that run perpendicular to the grooves (as the belt does twist and turn through the pulley system). If you belt shows signs of wear, replace the belt.
Step 3: Inspect the pulleys.
There are two pulleys on the 3.0 Vulcan that are apparently notorious for wearing out: The Tensioner pulley and the Idler pulley. They are the two pulley's that do not have any grooves on them (flat side of the belt goes against them). To test the pulleys, spin them. They should spin easily but quickly stop spinning. This is due to the fact that each pulley contains grease to coat the bearings inside. When there is no grease, the pulley will either (1) make a grinding noise or (2) spin easily and for a long amount of time (8-10 seconds). In either case where the pulley does not stop smoothly & quickly, the pulley has to be removed!
Step 4: Removing/Replacing the pulleys.
Then tensioner and idler pulleys each have a 15mm bolt on them that connects them to the engine block. Removal is towards the back of the engine (counter-clockwise). Remove the entire bolt and KEEP ALL THE PARTS. When purchasing the new pulley from a local part store, ONLY the pulley will be sold. Transfer the bolt and washer(s) that came off the old pulley to the new pulley and tighten down.
Step 5: Re-install belt.
The belt will go back on. One quick tip: The most common way will lend two pulleys to be last, the Alternator and the Idler pulley. It is easiest if the Alternator pulley is looped first leaving the Idler last. Because the idler pulley does not contain grooves it is easier to slip on. Also, use the Serpentine Belt tool to take tension off to assist in belt realignement.
Last: Before completing the job!
Ensure that the belt is flush with all the pulleys that have grooves (Alternator, Crankshaft, Water-pump, A/C
, and Powersteering). If the belt is not properly aligned, when starting the car, the belt may shred! Also, ensure that the routing diagram is followed completely. Mis-routing the belt can cause serious damage.
Start the car up and ensure that all the pulleys are running. Stand back before just putting your face down there though! The real test usually is when the engine has had plenty of time to cool down (i.e. mornings).
Hope this write-up, although simple, does help newbies like myself!
Serpentine Belt Routing Diagram (About.com)