Rattling Noise When Accelerating: What to Check First

A rattling noise when accelerating is a buzz, a tinny clatter or a sound like marbles in a can that starts as you press the gas. It can be a heat shield, one of the thin metal sheets over the exhaust pipe, shaking loose at its clip.

What matters is when it happens: pulling away uphill on a hot day, at one steady engine speed, only in the first seconds after a cold start, or with a warning light. Each points somewhere different, and one of them means you should stop driving.

Below is how to tell them apart in a driveway, which fixes the carmakers already pay for, and what the parts cost on the three models drivers ask about most. It comes from more than 20 carmaker documents and about 600 federal complaints that mention a rattle and acceleration together.

Why does my car rattle when I accelerate?

Because something metal is loose enough to shake when the engine works harder, or the engine itself is knocking. Pressing the gas raises the load and the engine speed, and a loose part has a speed where it buzzes.

The carmakers' documents name ten sources, and each one has its own moment, which is the clue a driver actually has:

1. Loose heat shield

A heat shield keeps exhaust heat off the floor, the fuel lines and the ground under the car, and a loose one makes a tinny buzz or rattle from underneath while you drive. With the engine off and cold, tap each shield by hand; GM's PIT5926A and Audi's 26 14 23 both name it, and telling it from knock is below.

2. Cracked exhaust pipe

A rattle or flutter from underneath as you accelerate, found with a shop's exhaust leak test. Subaru's bulletins 09-84-22R and 09-106-23R name it, and the Forester's pipe has a long warranty extension.

3. Engine knock

Knock is fuel burning at the wrong moment in the cylinder, a metallic rapping in Nissan's owner's manual, heard in gear under load, uphill or in heat. Fill with the octane your manual names; GM's PIP5233 ties it to octane, and Toyota's T-SB-0044-14 fixes it on some Tacomas with an engine computer update.

4. Rattle at one speed

Around 2,000 rpm on the gas in Ford's 18-2354, or cruising at 30 to 65 mph in Honda's A16060H. Ford's fix is a software update and Honda's is new rocker arms, and the low-speed section has both.

5. Cam phasers or chain

A rattle in the first seconds after a start. Check the oil level, then ask about the phasers; Ford's 23-2143 and GM's PIP5921B describe it, and the engine section has the detail.

6. Broken converter

It sounds like gravel in a can, loudest when you lift off the gas. Tap the converter shell with the engine cold, and our guide to bad catalytic converter symptoms covers the rest.

7. Torque converter studs

A rattle from the bellhousing, between the engine and the transmission. A dealer checks the spacer plate; Ford's 19-2358 covers it, at 5.5 to 6.5 hours.

8. Worn engine mount

A worn or broken mount lets the engine move under load. Nissan's PC601 campaign replaces the left mount on some 2016 to 2018 Rogues because it could break, and its FAQ says the engine can then drop onto the suspension member and make an abnormal noise.

9. Air filter housing

A buzz or rattle from the front of the car on acceleration or light load, between 1,300 and 1,700 rpm. GM's PIC6020 traces it on the 2013 and 2014 Cadillac ATS to missing rubber grommets under the engine air filter housing, a 0.3-hour job with the inspection.

10. Dash or front trim

Some rattles on the gas come from inside the car or the front trim, not the engine. Nissan traces one on the 2021 Rogue to heater hose clamps behind the dash, Ford one on the 2020 Escape 1.5L at 2,500 to 4,000 rpm to the park release cable, and Honda one on the 2016 and 2017 Pilot and 2017 Ridgeline to loose latches on the cover in front of the engine.

Rattling sound when accelerating at low speed

A rattle that comes only when pulling away at low speed can follow engine speed or road speed, and the documents describe both. Ford's bulletin for the 2018 F-150 5.0 describes a rattle when you press the gas at around 2,000 rpm, and an owner of a 2018 F-150 heard it at 1,500 to 2,000.

Honda's service news for its V6 Accord, Crosstour, Pilot and Odyssey names a rattle under light acceleration or a steady cruise from 30 to 65 mph instead. It puts it down to sticking rocker arms in the system that shuts off cylinders.

Two quick checks sort it. If the rattle comes when you rev the engine in Park, it follows engine speed; if it comes and goes with road speed whatever the gear, it's more likely something turning with the wheels, such as a wheel bearing.

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Is it a heat shield or engine knock?

Where it comes from and what changes it tell them apart: knock comes from the engine and changes with load and fuel, while a loose shield rattles from under the car. The two can sound alike, so the fuel test below is worth doing.

GM's bulletin for its 2021 to 2023 full-size trucks and SUVs puts a rattle from under the vehicle down to loose or missing heat shield clips, fixed with a new clip in 0.3 hours. Subaru's for the 2017 and 2018 Forester traces a rattle or flutter during acceleration to a cracked front exhaust pipe instead.

Knock has its own documents. GM tells dealers that a 2011 to 2013 Regal 2.0L can rattle on acceleration on fuel below 91 octane, and Toyota's bulletin for the 2012 to 2014 Tacoma with the 4.0L V6 names spark knock on light acceleration or uphill at 80°F or hotter.

Some knock is normal. Nissan's and Toyota's manuals call brief light knock while accelerating or climbing normal, and heavy knock that persists a problem.

The cheap test is the fuel door: fill with the octane your manual names and see if the rattle goes. GM's 2020 Silverado manual asks for 87, and highly recommends 93 for the 6.2 V8.

Engine rattling when accelerating

An engine rattle that isn't knock can be a timing part, and the documents place much of it at start-up rather than on the gas. Ford's bulletins for 2017 to 2020 F-150 3.5 EcoBoost trucks built by November 30, 2019 describe a rattle for 2 to 5 seconds after the truck has sat 6 hours or more, from the cam phasers, the parts that shift the camshaft timing on engine oil.

That's the same cold-start clue our timing belt symptoms guide gives for a worn chain. Ford also tells its dealers to check the oil level first when a 2018 F-150 3.5 sets codes P0365 or P0369, since low oil can set them.

Three more come from the documents, each narrower:

• A turbo's wastegate.Some 2024 CX-50 turbos built between February and July 2024 rattle when accelerating or idling from play at the wastegate arm, and GM tells dealers not to replace a Cadillac turbo for a brief rattle at the start or end of a pull once the converter bracket nuts check out.
• The torque converter.On 2018 and 2019 F-150 5.0 trucks built by February 12, 2019, Ford's bulletin says a rattle from the bellhousing may be converter studs hitting a spacer plate.
• A rod bearing.Hyundai's recall for some Alabama-built 2011 and 2012 Sonatas with the 2.0 or 2.4 describes a worn bearing's metallic, cyclic knocking noise. The recall says the engine can fail and stall, so that one means stop.

The wastegate is the valve that lets exhaust bypass the turbo; our P0299 guide covers what else it sets off.

Is it safe to drive with a rattling noise when accelerating?

Yes for a loose heat shield, since none of the heat shield bulletins we read treats one as urgent, but a warning light, lost power, or a knock that gets faster as the revs rise changes that. Any of those means stop, because they point to the engine or transmission rather than a loose sheet of metal.

Ford's 2012 F-150 manual warns that a misfire can overheat the catalytic converter and parts around it, possibly causing a fire, and a flashing check engine light is how the car tells you it's misfiring. A 2014 Santa Fe owner described a noise that sounded like a loose heat shield, just before the dash lights came on and the engine caught fire.

If the oil light comes on with the rattle, stop the engine. A rattle with shuddering or slipping belongs with our guides to bad transmission symptoms and CVT problems.

Don't leave a rattling exhaust leak for long either: the CDC warns that a small leak in the exhaust system can lead to a buildup of carbon monoxide inside the car.

Is there a recall or free fix for a rattle when accelerating?

A few, and one is still running for most cars under 150,000 miles: Subaru extended the front exhaust pipe warranty on the 2017 and 2018 Forester 2.5 to 15 years or 150,000 miles. Its bulletin names the rattle or flutter during acceleration directly.

The rest are narrower or finished:

• Nissan PC601.A free inspection and, if needed, a new left engine mount on 2016 to 2018 Rogues (the repair bulletin lists 2016 and 2017), because the mount could break. Its FAQ says a failed mount can let the engine drop onto the suspension member and make an abnormal noise.
• GM PIT5926A.New heat shield clips on 2021 to 2023 Silverado, Sierra, Tahoe, Suburban, Yukon and Escalade, under the bumper-to-bumper warranty.
• Mazda 01-013-24.A wave washer at the wastegate on some 2024 CX-50 2.5 turbos, under the powertrain warranty.
• Ford 21B10 and 21N03.The F-150 3.5 cam phaser programs. Both ended in 2022.

A bulletin, or TSB, is the written instruction a carmaker sends its dealers; it isn't a recall, so ask the dealer about it by its number. Run your VIN through our free VIN checker or NHTSA's recall lookup first.

How much does it cost to fix a rattle when accelerating?

Parts for the causes priced below run from $1.17 for an exhaust clamp to $1,260 for a catalytic converter. Labor separates the cheap fixes from the dear ones: GM's dealer time for a new heat shield clip is 0.3 hours, and Ford's for the 2018 F-150 5.0 software fix is 0.6.

The expensive ones are inside the engine or transmission, 5.5 to 6.5 hours for Ford's torque converter spacer plate and 9.5 to 9.7 for all four cam phasers on the F-150 3.5 EcoBoost.

RockAuto lists no exhaust heat shield for the 2018 F-150 5.0, the 2021 Silverado 5.3 or the 2016 Rogue, so on these a shield has to come from elsewhere, such as a dealer. GM's clip for its 1500 pickups is part 11602886.

How do you fix a rattling noise when accelerating?

By finding when it rattles before anyone replaces a part, because the cheap causes and the expensive ones overlap in sound. To fix a rattling noise when accelerating, work through the 6 steps below, in order:

1. Check the oil level. On level ground with the engine off: low oil can upset the cam phasers, and it costs nothing to rule out.
2. Note any warning light. A lit or flashing light, or lost power, means stop and have the codes read before driving on.
3. Run the VIN. Our free VIN checker shows open recalls and owner complaints, and a dealer can check bulletins by number for your car.
4. Try the right fuel. Fill with the octane your manual names; knock that goes away was knock.
5. Find where it lives. Rev it in Park, then listen at low speed in gear, and with the engine cold, tap each heat shield under the car by hand.
6. Get the fix quoted in parts. Ask whether it's the shield or only its clip, and for parts and labor on separate lines.

A heat shield rattle can end at step 5 with a new clip, as GM's does. If yours doesn't, our guide to jerking when accelerating covers mounts and the clunk they make.

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Common questions

Asked most often

What does a heat shield rattle sound like?

A tinny buzz or a rattle from under the car while driving. GM describes it as a rattle from under the vehicle while driving, from loose or missing clips.

Can low oil cause rattling when accelerating?

It can on engines whose cam phasers run on oil pressure. Ford tells its dealers to check the oil level first when a 2018 F-150 3.5 sets codes P0365 or P0369, and the phaser rattle it describes elsewhere is mostly at start-up.

Why does my car rattle when I let off the gas?

A catalytic converter broken inside sounds like gravel in a can, loudest when you lift off or when the engine is cold. Honda also names a buzz like a heat shield when gently letting up on the gas on 2016 to 2019 HR-V AWD models, fixed with software.

Can a transmission rattle when accelerating?

Yes. Ford's bulletin links a rattle from the bellhousing on 2018 and 2019 F-150 5.0 trucks built by February 12, 2019 to torque converter studs touching a spacer plate, and a transmission, clutch or torque converter comes up in 133 of the federal complaints about a rattle on the gas, though those are mentions, not confirmed causes.

Why does my car rattle when I start it?

A rattle for the first 2 to 5 seconds after a cold start is the pattern Ford gives for worn cam phasers on the F-150 3.5, and a stretched timing chain also rattles in the first seconds after a cold start. It's a start-up noise rather than an acceleration one.

Why does my car rattle at highway speed?

Honda names a rattle while cruising at 30 to 65 mph on its V6 Accord, Crosstour, Pilot and Odyssey, from sticking rocker arms in the system that shuts off cylinders. A noise that rises and falls with road speed rather than engine speed points at something turning with the wheels instead, such as a wheel bearing.

Prices are ranges compiled in September 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.