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Squealing belt noise
Medium — fix within days
You hear a high-pitched squeal from under the hood, usually loudest on a cold start or when you turn the steering wheel. The squeal may fade as the engine warms up.
Possible causes
- Worn serpentine belt — Most likely
Check first: Look at the belt with the engine off. Cracks, missing chunks, or a shiny glazed surface mean the belt is worn out. - Loose or worn belt tensioner — Possible
Check first: Press the belt with your finger with the engine off. If it moves more than about half an inch, the tensioner may be weak. - Failing alternator bearing — Less likely · Codes: P0620
Check first: Turn on the headlights and the air conditioning. If the squeal gets louder with more electrical load, the alternator bearing may be failing.
Questions, answered
What usually causes this?
The most likely causes are: Worn serpentine belt; Loose or worn belt tensioner; Failing alternator bearing. If you are not sure what is wrong, have it checked by a qualified technician.
Is it safe to drive with this symptom?
Drive with caution and book a check within days. Do not ignore it.
Not repair advice. If you are not sure what is wrong, have it checked by a qualified technician. Cars differ by make, model and year.
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