The Infiniti Q50 is a well-engineered luxury sedan, but some owners have reported an issue where the rear end bounces excessively when hitting a bump. This can make the ride uncomfortable and impact vehicle handling. Below, we analyze the common causes of this issue and provide effective solutions.
Common Causes of Rear Bounce in the Infiniti Q50
1. Worn-Out or Failing Shock Absorbers
One of the most frequent causes of excessive bouncing in the rear of the Q50 is failing shock absorbers. Shocks are designed to dampen the up-and-down motion of the suspension. When they wear out, the vehicle loses stability, causing a noticeable bounce when hitting a bump.
Symptoms of bad shocks include:
- Excessive bouncing after going over a bump
- Uneven tire wear
- Increased braking distance
- Poor handling and control
Solution: Replace the worn shock absorbers with high-quality OEM or performance shocks such as Bilstein B8 Performance Plus or KYB Gas-A-Just for a firmer ride and improved control.
2. Weak or Worn Rear Suspension Components
If your control arms, bushings, or sway bars are worn out, they may not properly stabilize the suspension, leading to excessive bouncing.
Symptoms of worn suspension components:
- Clunking or knocking noises when going over bumps
- Loose or imprecise steering feel
- Uneven vehicle height or sagging in the rear
Solution: Inspect and replace worn-out control arm bushings, sway bar links, and trailing arms to restore proper suspension performance.
3. Overly Soft or Worn Rear Springs
Coil springs play a critical role in absorbing road impacts. If they are too soft or worn, the vehicle may continue bouncing after a bump.
Symptoms of bad springs:
- Vehicle sits lower in the rear
- Increased body roll during turns
- Bouncing sensation over bumps
Solution: Upgrade to stiffer springs such as Eibach Pro-Kit Performance Springs to enhance ride stability and reduce excessive bounce.
4. Tire Pressure and Alignment Issues
Incorrect tire pressure or misalignment can also contribute to bouncing issues.
Symptoms of tire-related issues:
- Uneven tread wear
- Steering pulling to one side
- Bumpy or rough ride quality
Solution: Ensure that tire pressure is set to manufacturer specifications (typically 32-35 PSI for the Q50). Additionally, have a professional perform a four-wheel alignment.
5. Aftermarket Modifications Affecting Suspension
Owners who have installed lowering springs, coilovers, or aftermarket wheels may experience increased bouncing due to improper tuning.
Common problems include:
- Excessive stiffness leading to poor shock absorption
- Incorrect suspension geometry affecting handling
- Mismatched components causing imbalanced ride quality
Solution: Ensure that all aftermarket parts are properly installed and adjusted. High-quality coilovers like BC Racing BR Series or KW V3 offer adjustable damping to fine-tune ride comfort.
6. Faulty Rear Suspension Dampers or Struts
In some cases, the electronic damping control system found in higher trims of the Infiniti Q50 may malfunction, leading to a rough ride.
Symptoms of faulty dampers:
- Harsh or excessively soft ride
- Warning lights on the dashboard
- Uneven suspension response
Solution: Have the dampers inspected and recalibrated or replace them with new ones.
Preventative Maintenance to Avoid Rear Bounce Issues
To keep your Infiniti Q50’s suspension in optimal condition, consider the following maintenance tips:
- Regularly inspect shock absorbers for leaks or damage
- Check and replace suspension bushings when worn
- Maintain proper tire pressure and alignment
- Avoid excessive lowering that disrupts suspension geometry
- Invest in quality suspension components for long-term durability
Final Thoughts
If you experience rear-end bouncing when hitting a bump in your Infiniti Q50, addressing the root cause is essential for safety and comfort. Whether it’s worn shocks, weak springs, or suspension misalignment, resolving the issue with the correct parts and adjustments will significantly improve your vehicle’s ride quality.
