Why is my car shaking when idling?
A car that shakes or vibrates at idle but smooths out as you drive usually has a misfire (worn spark plugs or ignition coils), worn engine mounts, or a vacuum or air-intake issue. A scan and a quick check of the mounts and plugs usually points straight to it.
The most common causes
Worn spark plugs or a failing ignition coil make a cylinder stumble at idle; often pairs with the engine light.
Engine light may be onPerished mounts let the engine's shake transfer into the cabin, worst at idle or in gear.
Worse in gear / at lightsAn unmetered air leak upsets the idle and makes it rough or hunting.
Carbon build-up on the throttle or idle valve makes the idle uneven.
A dirty fuel injector or a sensor reading wrong can cause a rough, shaky idle.
What it costs in Sydney
| Mobile diagnostic + scan | $129 |
| Spark plugs / coils / mounts | Quoted on inspection |
The $129 is credited toward the repair if you book it with us.
Get it diagnosed — in your driveway.
We scan it, check the plugs, coils and mounts, and give you a fixed price to smooth it out.
Common questions
At idle the engine's running slowest, so a misfire or a worn mount shows up most. Once you're moving it smooths out — but the underlying fault is still there.
Yes — perished mounts let the engine's shake into the cabin, and it's usually worst in gear at the lights. We check the mounts as part of the diagnostic.
$129 for the mobile diagnostic, credited toward the repair if you book it with us.