Why does my car shake at idle?
Idle shaking can come from a combustion misfire, incorrect air/fuel mixture, an engine mount, or an accessory load. The warning-light behavior and whether it changes warm versus cold separate these branches.
Plausible causes
- Ignition, fuel, air-leak, or compression misfire
- Engine or transmission mount
- Charging or accessory-load problem
Useful next checks
- Record whether it occurs cold, hot, in gear, or with A/C
- Preserve OBD codes and freeze-frame data
- Arrange cylinder-specific tests before replacing parts
Related OBD codes
Sources and method
This answer provides hypotheses and a verification plan, not a component verdict. Exact repair procedures require authoritative service information for the specific vehicle.
NHTSA vPIC Vehicle APISAE J2012