What Causes the Rear-End Noise at Low Speed in the New Buick Regal?
3 Answers
There are many possible causes for "abnormal noises" from the car chassis: 1. Loose or deformed chassis components causing noise. 2. Noise originating from tire tread patterns. 3. Noise coming from internal components of the engine or transmission in the chassis area. 4. Noise from various connecting parts of the drivetrain. 5. Noise from front or rear wheel bearings. 6. Noise caused by human error during maintenance, installation, replacement, or repair, such as improperly tightened screws, component interference, incorrect positioning, or reverse installation due to negligence or carelessness. This can be very dangerous. 7. Noise from critical safety components: for example, in the braking system, it could be due to worn brake pads reaching their limit and grinding directly against the disc; or chassis noise caused by lack of oil in the power steering system.
Recently, my Buick Regal also encountered a situation where there was a strange noise at the rear of the car at low speeds, sounding like a creaking noise. Later, I found out that the rubber bushings of the rear suspension had aged. After four or five years of driving, the chassis components of this car tend to have such issues. When driving over speed bumps at low speeds, the rubber compresses and rubs, causing noise, which becomes more noticeable when going over potholes. It could also be due to wear on the shock absorber top mount or cracks in the stabilizer bar bushings. Over time, these rubber parts can harden and crack. Additionally, unsecured items in the trunk can rattle and make noise, so it's recommended to empty the trunk first to test. If the noise persists, it's best to take the car to a shop for a lift inspection of the chassis. Replacing a set of bushings only costs a few hundred dollars.
My Buick Regal used to make a clunking noise from the rear wheels when turning at low speeds, which turned out to be caused by poor brake caliper retraction. At low speeds, the brake pads didn't fully separate from the rotors, resulting in friction noises. This issue can occur even on new cars, especially after rain or car washes. Another possibility is loose rear wheel bearings - you might hear a metallic humming sound at low speeds. The exhaust system should also be checked; if the exhaust pipe hangers are deformed, they may knock against the frame when the car moves. Unsecured tools in the trunk can also cause noises. I recommend first trying to identify the pattern of the noise (e.g., does it only occur at certain speeds?) before having a mechanic focus on inspecting the suspension and brake systems.
