Skip the auto shop - Our mechanics make house calls

Q: Just bought a used Forester that started rattling when I'm not accelerating and the wheel is straight. Any ideas on what it could be?

asked by on

When the car is started and there is no acceleration I can sometimes hear a rattling noise coming from the right side of the car, between the engine and the wheel somewhere. If I accelerate at all the noise goes away. Also, It only seems to rattle if the wheel is straight, most the time turning the wheel one way or another reduces or eliminates the sound. The noise is there regardless of gear, but when going from N to R or to D the rattling sometimes gets quieter while gears are changing but returns to normal intensity once the gear is set. (Sometimes the noise is uneffected by gear changes) The car also pulls very slightly to the right. And... If I turn the AC on I do notice a change in the rattle, but can't tell if I'm just noticing additionally noise from AC. Regardless though the rattling doesn't happen ever when I'm accelerating

My car has 150000 miles.
My car has an automatic transmission.

A: Hey there. The most common source of rattle...

Hey there. The most common source of rattles on Subaru’s are the exhaust heat shields. They can rattle under all sorts of random circumstances. Whenever you turn, accelerate, let off the gas or brake, the motor experiences torque that is dampened by the engine mounts so the passengers won’t feel these vibrations. This torquing will affect the exhaust as much as any other component on the car. Checking for exhaust shield rattles is fairly simple. Use a soft mallet hammer to tap on the shields to see if it rattles. If it does, repairing this is more challenging than locating it. It’s a creative process that can only be decided in person. Of course, you will need to get under that car to access all of the shields.

Other than the exhaust shields, it could be a dust shield on the brakes or a sway bar end link. Both of these are far less common as determined by your description of your symptoms. If it is a sway bar end link, it will rattle most often when you go over bumps. If it is the brake dust shield, you will need to remove the wheel to see if the shield is loose.

If you need further help having this done, a certified professional from YourMechanic can come to your car’s location to diagnose the rattling noise so that this can be corrected.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Battery light is on durign acceleration or on bumpy roads

When the battery light comes on in vehicles it is due to the voltage falling below the required 12.6 volts. This voltage is required for all the vehicles' electrical systems to work properly. The most common causes of the battery...

Q: Clutch won't go into gear

Having difficulty moving into first gear and then being unable to move your Subaru into any other gear leads me to believe that there are problems with one or more components in the clutch system. While the information you offered...

Q: Pulling during deceleration

Hello. I would check for uniformity of tire pressure in all four tires. Check for brake drag and failure to release at each wheel. A likely cause is an alignment or frame issue. Check that camber is within FSM specification...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...