* Belt itself: The belt might be worn, cracked, glazed, or simply too loose. A worn belt will squeal, especially when it's under tension. Check for cracks, glazing (shiny areas), and fraying on the belt's surface. Also, visually inspect the belt's tension. A loose belt will slip, causing the squeal.
* Pulley(s): One or more pulleys (the wheels the belt rides on) could be worn, damaged, or seized. Look closely at each pulley for signs of damage like grooves, rust, or roughness on the pulley face. A seized pulley will not rotate freely, causing the belt to squeal. Pay particular attention to the alternator, power steering pump, and air conditioning compressor pulleys.
* Idler/Tensioner pulley: This pulley keeps the belt taut. If it's worn or failing, it won't maintain proper belt tension, leading to squealing. Often, a failing tensioner pulley will also make a clicking or groaning noise.
* Water pump: While less common, a failing water pump bearing can also cause a squeal, especially if the pump is driven by the serpentine belt.
Troubleshooting Steps:
1. Visual Inspection: With the engine OFF, carefully inspect the belt and all pulleys for the issues mentioned above. Use a flashlight to get a good look.
2. Belt Tension Check: If you're comfortable, you can check the belt tension. The belt should have a slight give (about ½ inch of deflection) when pressed firmly midway between the pulleys. Consult your owner's manual for the correct tension specification. If the tension is incorrect, it's likely a problem with the tensioner pulley.
3. Listen Carefully: With the engine running, try to pinpoint the source of the squeal by listening closely to each pulley. A stethoscope (even a long screwdriver held against your ear) can help.
4. Spray Test (Use with Caution!): With the engine running, carefully spray a lubricant (like silicone spray or belt dressing – *not* WD-40) onto the belt while it's running. If the squeal temporarily stops, it points to a problem with the belt or pulleys. Be extremely cautious when doing this; ensure your hands, clothing, and surrounding areas are clear of moving parts.
If you are not comfortable performing these checks, take your Saturn to a qualified mechanic. Ignoring a squealing belt can lead to more serious damage, including belt breakage, which can cause significant engine damage. Replacing a belt is relatively inexpensive, but ignoring the problem can lead to costly repairs later.
