* Engine Heat: The most likely culprit. Hot pulleys can expand, making the belt ride improperly, causing slippage and ultimately shredding. Always let the engine cool completely (at least an hour) before attempting any belt replacement.
* Incorrect Routing: Even if you followed the diagram, it's easy to make a mistake under pressure (or while the engine is hot). Double-check *every* pulley to ensure the belt is routed correctly. One misplaced position can lead to the belt rubbing against something, causing rapid wear.
* Damaged Pulley: A bent, damaged, or misaligned pulley can cause excessive belt stress and wear. Carefully inspect all pulleys for damage. Look for grooves, cracks, or anything that's not smooth and round.
* Water Pump Bearing: A failing water pump bearing can seize up, putting immense strain on the belt. This is a particularly common cause of belt failure. Listen closely to the water pump for unusual noises.
* Idler Pulley Bearing: Similar to the water pump, a failing idler pulley bearing causes increased friction and belt stress.
* Power Steering Pump: A failing power steering pump can also be a significant source of strain, especially if it's seizing up.
What to do:
1. Let the engine cool completely. This is paramount.
2. Visually inspect every pulley and component the serpentine belt contacts. Look for damage, wear, or misalignment.
3. Carefully re-route the serpentine belt, following the diagram precisely. Take your time and double-check each pulley. A poorly-installed belt is almost guaranteed to fail quickly.
4. Check the tension. The belt should have a slight deflection (usually specified in the repair manual). Too tight can damage components; too loose will cause slippage.
5. If any pulleys or components show signs of wear or damage, replace them *before* installing a new belt. A new belt will quickly shred if forced to compensate for faulty parts.
6. Consider professional help: If you're unsure about any step, it's best to consult a mechanic. Continuing to try and fix this while the engine is hot or without properly diagnosing the underlying issue is a recipe for further damage and potential injury.
Ignoring the underlying issue will only lead to repeated belt failures, potentially causing more significant and expensive damage to your engine.
