Symptom guide
Car Vibrates at Idle
How to narrow down vibration while stopped or idling.
Quick answer
Idle vibration can come from misfires, rough idle mixture, worn engine mounts, dirty throttle body, vacuum leaks, or injector problems.
Most likely causes
- Ignition misfire
- Worn engine mounts
- Vacuum leak
- Dirty throttle body
- Fuel injector problem
Basic driver checks
- Notice whether vibration changes in park, drive, or reverse.
- Scan for misfire and fuel trim codes.
- Listen for hissing.
- Check whether RPM is steady or wandering.
DIY diagnostic path
- Do not ignore a flashing check engine light.
- Record cold versus warm idle behavior.
- Inspect obvious loose intake hoses.
- Avoid replacing mounts before ruling out a misfire.
Common mistakes
- Replacing mounts when the engine is misfiring
- Ignoring injector circuit codes
- Assuming idle vibration is normal aging
What to tell the mechanic
Tell the shop whether the vibration is felt more in the seat, steering wheel, or whole body and whether RPM changes.