Car Shaking When Idle? What the Shake Is Telling You

A car shaking when idle is your engine telling you something, and where you feel the shake is the first clue. It often shows up at a red light and disappears once you're back on the road.

GM says the Drive-only shake on some of its trucks will not be present in Park, or Neutral, so a few seconds at a stop can already narrow it down. Honda CR-V owners describe the same thing, and one of them shifts to Neutral at stop lights.

This page covers when it's not safe to drive, the causes, the timing clues, what a fix costs and what carmakers repair. It comes from owner's manuals, carmakers' service bulletins and owners' complaints to NHTSA, the federal safety agency.

Is it safe to drive when your car shakes at idle?

No, not if the check engine light is flashing: a flashing light means your engine is misfiring, say Ford's and Honda's manuals. Honda tells you to park somewhere safe, away from anything that can burn, and let the engine cool; our flashing check engine light page has the rest.

Ford's manual warns that a misfire can overheat your exhaust and damage your catalytic converter, and even start a fire. GM's tells you to slow down, and if the light keeps flashing, to park, restart and see a dealer as soon as possible.

If you see a steady light or no light at all, it's less urgent, so drive gently to a shop for a test. If the shake ends with the engine stalling at a stop, our car shuts off page picks up from there.

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What the manuals say 3 manuals

• 2012 Ford F-150, page 13. A blinking light means engine misfire, which could damage the catalytic converter; drive in a moderate fashion and have it serviced immediately. Misfire can overheat the exhaust, possibly causing a fire.
• 2018 Honda Odyssey, page 717. Blinks when the engine misfires: park in a safe place with no flammable items and wait at least 10 minutes with the engine stopped; if it blinks again, drive to the nearest dealer at 31 mph or less.
• 2020 Chevrolet Silverado, pages 135–136. Flashing: reduce speed, avoid hard acceleration and hills; if it keeps flashing, park, turn the engine off for 10 seconds and restart; if still flashing, see a dealer as soon as possible.

Why is my car shaking when idle or stopped?

Your car shakes when stopped or idling because its engine is running unevenly, or because the mounts that hold it are passing its shake through to you. For a car shaking when stopped, carmakers' manuals and service bulletins, the repair notes they send their dealers, point to four causes, and each has a test that should come before any part:

These rough idle causes follow the table's order, each with what it is and what you can check. The bulletins behind them are in the data list at the end of this section.

1. A misfire

A misfire means one cylinder isn't burning its fuel properly, so your engine loses its even beat and you feel it as a shake. A worn spark plug, a failing ignition coil or a fuel injector can each cause one, and our P0300 page explains the misfire codes.

The check engine light is your best clue here, steady or flashing. Your shop reads the code, which can name the cylinder, and then tests or swaps that cylinder's coil and plug before buying anything.

2. Engine or transmission mounts

Mounts are the rubber-filled brackets that hold the engine and transmission and soak up their normal shake. When one wears out or sits wrong, you feel it in your seat and steering wheel, and GM says it shows most at a stop in Drive.

A mount problem doesn't have to mean new mounts: GM's fix for some trucks is re-centering them or adding spacers. A clunk or rattle from the mounts when you accelerate is covered on our rattling noise when accelerating page.

3. A vacuum leak

A vacuum leak lets extra air into your engine that its sensor doesn't count, so the fuel mix runs lean and the idle stumbles. Our vacuum leak page covers the signs and the parts that leak.

If you hear a hiss under the hood, or get a code for a lean mix, look this way. A shop's smoke test shows you where the air gets in, before you pay for any part.

4. Idle speed or engine software

Some shakes come from how your engine is set to idle, not from a worn part. Carmakers have fixed idle shakes with software updates, including ones where the idle felt too low and no warning light came on.

Nissan goes further for some trucks and SUVs: its bulletin says not to replace the mounts unless they're visibly leaking. So ask whether your carmaker has an update for an idle shake before you pay for parts.

Idle-shake bulletins 10 bulletins

• Nissan NTB13-021b (March 2017). 2010–15 Frontier, 2010–12 Pathfinder and Xterra, 4.0L V6: low or rough idle with no codes; don't replace engine mounts unless visibly leaking; engine software and, on the Frontier, an exhaust center tube with a mass damper.
• GM PIP5137 (July 2013). 2014 Silverado and Sierra 1500 5.3L: rough idle or vibration at idle in gear, like idling too slow; center the engine and transmission mounts, then shim the right mount 3 mm.
• GM PIP5211F (October 2016). 2014–17 Silverado and Sierra 1500, 2015–17 Tahoe, Suburban, Yukon and Escalade: rough idle in Drive, not in Park or Neutral, no codes; engine mounts grounding out; spacers, or new mounts if the vibration measures high.
• Honda SB 15-046 (August 2015). 2015 CR-V: seat vibration while stopped in gear, and at 15–30 and 40–50 mph; a software update for the 40–50 mph one only, normal warranty.
• Ford SSM 46549 (April 2017). 2017 Focus 1.0L built February 27 to April 12, 2017: excessive engine idle vibration; check the engine torque restrictor part number.
• GM 24-NA-244 (April 2025). 2024–25 Traverse and Acadia, 2025 Enclave: cold-start rough idle, code P050D may be set; engine software.
• Nissan NTB15-004 and Infiniti ITB15-003 (January 2015). 2013–14 Pathfinder, 2013 JX35 and 2014 QX60: low, rough or uneven idle in Drive with the AC on; engine software if the part number matches.
• Hyundai 21-AT-001H (January 2021). 2018–19 Sonata 2.4L: rough idle only at a stop in Drive, AC off, transmission warm; transmission software.
• Hyundai 17-AT-004 (June 2017). 2017 Elantra 2.0L and Santa Fe Sport 2.4L: rough idle in Drive after stopping; a transmission solenoid.
• Toyota T-TT-0362-15 (September 2015). Many 1998-2012 models: low or rough idle after the battery is disconnected; clean the throttle body.

Why does it shake at idle but smooth out while driving?

A car shakes at idle but smooths out while driving because at idle your engine turns at its slowest speed, where an uneven engine or a grounding mount shows most. The carmaker documents on this page describe shakes at a stop in gear that you don't feel on the move.

A car that only shakes at red lights is at least considerate about it: it waits until you've stopped. Once you drive, the engine speeds up and the idle problem can hide, but it hasn't gone anywhere.

If it also shakes at certain road speeds, look for a second cause; one Honda bulletin describes a car that does both. If it only shakes when you accelerate, read car jerks when accelerating; if only when braking, read steering wheel shakes when braking.

Why does it shake in Drive but not in Park?

It shakes in Drive but not in Park because of the mounts or the idle setting, going by the carmakers' bulletins. GM's truck bulletin says its Drive-only rough idle won't show in Park or Neutral, and Hyundai fixed one on a sedan with transmission software.

Owners notice it too. One CR-V owner wrote, I have resorted to putting the vehicle in Neutral at stop lights which helps.

You can notice this safely at any stop, and the check takes a few seconds and no tools. Keep your foot on the brake throughout and work through the 4 steps below, in order:

1. Stop with your foot firmly on the brake. Keep it there the whole time, and don't press the gas.
2. Feel the shake in Drive. Note whether it's in the seat, the steering wheel or the whole car.
3. Shift to Park. Note whether it still vibrates in Park, or the shake goes away or gets worse.
4. Tell the shop what you felt. Say whether it changes after a long drive, since GM says its Drive-only shake shows most then.

If you get a rough idle in Park as well as in Drive, the engine itself is running unevenly, so a misfire, a vacuum leak or the idle setting comes first. GM's truck bulletin says its mount shake doesn't show in Park, so one that stays there points away from the mounts.

Never rev the engine in gear against the brake to make it shake harder. That's a test for the shop to do with the car secured, not something to try at a light.

When does it shake: on startup, cold, with the AC on, or after a repair?

When the shake comes and goes is a clue you can collect for the shop. If your car shakes when you start it, or only with the AC on, write that down, because the timing narrows the causes:

• Right after you start it, cold. GM fixes a rough idle on a cold start in some newer SUVs with a software update, and the engine may store a code for it (P050D). If your car shakes when you turn it on and settles as it warms up, tell the shop.
• After a long drive. GM says its trucks' Drive-only shake shows most after extended driving or hard acceleration, and changes with temperature.
• Only with the AC on. Nissan and Infiniti update the engine software on some 2013–14 Pathfinders, JX35s and QX60s for a low or rough idle in Drive with the AC on. Compare AC on and off at a stop and tell your shop.
• After a repair or a new battery. Toyota says many of its 1998-2012 models can idle low or rough after the battery has been disconnected, and its fix is cleaning the throttle body. After any other repair, tell your shop exactly what was done.

If your car shakes when starting and then stalls, that's a different case, and our car shuts off page covers it. Either way, you'll get further with your shop if you can say exactly when the shake shows up.

Can a bad battery, alternator or belt cause a rough idle?

Not a bad battery, alternator or belt: we found no carmaker document that ties them to a rough idle, though spark plugs, coils and a dirty throttle body can cause one. Here's what can and can't cause a car to shake at idle, going by the sources on this page:

• Bad spark plugs. Yes: worn plugs and failing coils cause misfires, the first cause above, and the P0300 page has the codes.
• A dirty throttle body. Yes: Toyota's fix for a rough idle after a battery disconnect is cleaning the deposits off it.
• Carbon on the valves or poor fuel. Yes: GM ties carbon build-up to a rough idle and misfire on its 2000-2025 gas engines, and suggests Top Tier fuel for a rough idle in cold weather on the 2013–14 Cruze and Sonic.
• A bad O2 sensor. Shops name it as a cause too; ask them to read its live data on a scan tool before replacing it.
• Injectors, the air filter or the airflow sensor. Shops check these too, along with compression and the exhaust. Have each one tested before it's replaced.
• The battery or the alternator. We found no carmaker document that ties a bad one to a shake at idle; a disconnected battery is a different case (see above). What they do cause is on our battery light and bad alternator or battery pages.
• The catalytic converter. Ford's manual says a misfire can damage it, so a shake with a flashing light can end up costing one. Its own signs are on our bad catalytic converter page.
• The serpentine belt. We found no carmaker document that names it as a cause of an idle shake.

Low oil, low transmission fluid, a bad starter or oil pressure sensor? We found no carmaker document that ties any of them to a rough idle, so get the shake tested on its own.

Carbon and fuel bulletins 2 bulletins

• GM 16-NA-383 (June 2024). 2000-2025 GM gas engines: rough idle, extended crank or misfire codes P0300–P0308 from carbon on the valves; a cleaning kit, and Top Tier fuel with regular oil changes.
• GM PI1206A (July 2014). 2013–14 Cruze and Sonic 1.8L: check engine light and rough idle at 14–50°F with code P0300; Top Tier fuel, and no parts replaced.

How much does it cost to fix a rough idle?

A spark plug costs $1.49 – $11 and an ignition coil $19 – $135, parts only, on the three vehicles priced below. The first box covers five parts, from plugs to mounts, and the second what a shop charges for the common jobs:

Before you pay for mounts, try the Drive-versus-Park check above and ask about bulletins, since GM fixed some Silverado shakes with spacers instead of new mounts. Fitted at a shop, coils and plugs cost far more than the parts:

How do you fix a rough idle?

Fix it in the order of the tests, so you only pay for the part the test names. Work through the 5 steps below, in order:

1. Check the light. If it's flashing, ease off and park safely; if it's steady, get the codes read.
2. Compare Drive and Park. At a stop, foot firmly on the brake and no gas, note whether the shake changes.
3. Note when it happens. Cold start, after a long drive, or only with the AC on.
4. Ask about bulletins. Ask the dealer or your shop whether your model has a bulletin or software update for an idle shake.
5. Test before parts. A code read for a misfire, a smoke test for a vacuum leak, and a mount check for a Drive-only shake.

If the shop can't find it on the first visit, tell them exactly when it happens. GM notes that its Drive-only shake can be hard to recreate and changes as the engine cools, so your notes save time.

A good answer tells you what the codes said, whether the shake changes between Drive and Park, and which bulletin was checked. If all you get is a list of parts with none of that, question it.

Common questions

Asked most often

What is a rough idle?

It's an engine that runs unevenly at its slowest speed, which you feel as a shake or a stumble while stopped. A misfire, worn or badly seated mounts, a vacuum leak or the idle setting can cause it.

Is it safe to drive a car that shakes while idling?

If the check engine light is flashing, no: that's a misfire, so ease off and park somewhere safe. With a steady light or no light, drive gently to a shop for a test.

Why does my car idle rough but drive smoothly?

Idle is the engine's slowest speed, where an uneven engine or a mount that's grounding out shows most. Once you drive, the faster engine can hide the problem without fixing it.

Why does my car shake in Drive but not in Park?

That pattern points at the mounts or the idle setting. GM says its Drive-only rough idle on some trucks doesn't show in Park or Neutral at all.

Why does my car shake when I turn it on?

A shake right after a cold start can come from the engine's cold-start idle, and GM fixes one such case with software. If it settles as the engine warms, tell the shop exactly that.

Can low oil cause a car to shake?

We found no carmaker document that ties low oil to a shake at idle. Check the dipstick and top it up to the mark your manual gives, then get the shake tested on its own.

Can a bad transmission cause shaking at idle?

It can: Hyundai fixed a rough idle at a stop in Drive on one of its sedans with transmission software. Owners mention the transmission in 325 of 1,932 idle-shake complaints, but a Drive-only shake points first at the mounts, as GM's bulletins describe.

How do you fix a shaky idle?

Test before you buy: read the codes, compare Drive and Park, and ask about bulletins. Then replace only the part the test names, whether that's a coil, a plug, a hose or a mount.

Prices are ranges compiled in August to October 2026 for the US market and vary by region, engine and shop rate. Prices from $10 up are rounded to the nearest dollar, so $14.13 reads as $14 and $14.52 as $15. Below $10 they're exact. This article is general information, not advice about your specific vehicle. See the disclaimer.