INDEPENDENT REFERENCE
Rough idle
Engine vibration at idle can come from air, fuel, ignition, mechanical or mount problems.
Understanding the symptom
Engine vibration at idle can come from air, fuel, ignition, mechanical or mount problems.
Possible causes to investigate
Vacuum leak; ignition fault; fuel delivery issue; deposits; engine mount wear.
Safe observations
Note cold/hot behavior and fault codes; compare idle response with accessories on or off.
When to stop and get help
A flashing malfunction light warrants stopping to avoid catalyst damage.
A symptom alone cannot establish a physical diagnosis. Arrange competent inspection where safety is uncertain.