Why Does the Noise Increase After Installing New Shock Absorbers?
3 Answers
1. Suspension system noise: Although this falls under the category of normal aging, different users may experience significantly different results. A large part of the noise is caused by wear and tear of the wheel hub bearings or a reduction in the damping capacity of the shock absorber fluid. There are also many cases where the shock absorber fluid has completely leaked out. Since the vehicle's shock absorption performance relies on both the shock absorber fluid and the springs, the loss of the fluid's effectiveness can significantly increase noise. 2. Engine and accessory noise: This is due to the normal wear and tear of internal engine components over time. If there have been previous abnormal incidents, such as unnoticed oil leaks or coolant leaks, the noise from such engines will be more pronounced, with the level of noise varying depending on the severity of the incident. 3. Exhaust pipe noise: This is part of normal aging. For exhaust pipes that are around 10 years old or have traveled approximately 200,000 kilometers, frequent exposure to acidic and alkaline mixtures like mud and water at the bottom of the vehicle body may lead to rust-induced leaks, thereby increasing noise at the rear of the vehicle.
I've seen too many cases of strange noises after suspension replacements, most of which were caused by installation issues. Mechanics relying on feel instead of using a torque wrench to tighten bolts is unacceptable—too loose and it squeaks, too tight and the parts deform, causing noise. If the dust boots aren't properly installed, metal-on-metal friction during bumps creates a harsh screeching sound. Then there are cases where the top mounts are worn but not replaced together—new shocks pressing against them sound like a rickety old chair creaking. Even worse is buying aftermarket parts that don’t fit properly; a millimeter of mismatch makes the entire strut tower clunk three times louder than the original setup. My advice? If new noises appear after replacement, don’t tough it out—go back to the shop immediately and have them recheck every bolt’s torque and the positioning of all rubber boots. You didn’t pay good money for shoddy work.
After replacing the shock absorbers, it's even noisier? First, check if the springs aren't seated properly. A friend of mine experienced a clunking noise on rough roads after replacement, only to find the spring base wasn't aligned with the locating slot. Also, a hissing sound like air leaking is likely due to the shock being installed crooked, causing uneven piston movement. If there's a loud thud over speed bumps, suspect the upper mount bearing is seized—grinding noises are common in such cases. Some cars come with factory-installed bump stops; if the mechanic forgets to remove the old rubber stops, they can cause odd noises. A word of caution: aftermarket parts vary in quality, and those with poorly machined internal valves can produce a gurgling sound like boiling porridge when driving. These issues often require a professional lift to diagnose properly.
