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Engine knocking sound
High — fix right away
You hear a metallic knocking or pinging sound from the engine, often when you accelerate or drive uphill. The sound speeds up with the engine.
Possible causes
- Low-octane fuel or carbon buildup — Most likely · Codes: P0325P0327P0328
Check first: Notice when the knock happens. If it is worse under load or uphill, try a tank of higher-octane fuel and see if it goes away. - Worn engine bearings — Possible · Codes: P0521P0524
Check first: Listen as the engine warms up. A knock that gets louder when hot, plus low oil on the dipstick, points to worn bearings. - Bad knock sensor — Less likely · Codes: P0325
Check first: If the check engine light is on and the knock is faint, the knock sensor itself may be bad. A scan tool will show a knock sensor code.
Questions, answered
What usually causes this?
The most likely causes are: Low-octane fuel or carbon buildup; Worn engine bearings; Bad knock sensor. If you are not sure what is wrong, have it checked by a qualified technician.
Is it safe to drive with this symptom?
No — stop driving and get it checked. This symptom can mean a serious problem.
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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