ASE G1 Auto Maintenance and Light RepairEngine SystemsMedium
A vehicle's serpentine belt is squealing loudly, especially on cold starts and when turning the steering wheel. Technician A says this could be caused by a worn or stretched belt. Technician B says this could be caused by a failing power steering pump. Who is correct?
- ATechnician A only
- BNeither Technician A nor Technician B
- CBoth Technician A and Technician B
- DTechnician B only
Show answer & explanationAnswer & explanation
Correct answer: C. Both Technician A and Technician B
Both technicians are correct. A worn, stretched, or glazed serpentine belt can slip, causing a squealing noise. Additionally, a failing accessory driven by the belt, such as a power steering pump that is binding or seizing, can put excessive drag on the belt, causing it to slip and squeal.
Why the other options are wrong
- A. A worn or stretched belt can definitely cause squealing due to slipping.
- B. Both technicians provide plausible and correct causes for the symptom.
- D. A failing power steering pump (or any other accessory) can cause the belt to squeal due to excessive drag.
Serpentine Belt Squeal Causes
Squealing noises from the serpentine belt can be caused by the belt itself (worn, loose) or by a failing accessory component it drives.
- Belt slipping on pulleys creates the noise.
- Causes: worn belt, loose tensioner, failing accessory (alternator, A/C compressor, power steering pump).
- Often worse when cold or under load (e.g., turning).
Memory trick: Belt squeals, two tales: belt's worn or pump fails!