Rear suspension sagging on my 2023 Buick Envision Avenir

ClearTheCode admin answer:

Rear suspension sagging on a relatively new 2023 Buick Envision Avenir with only 15,000 miles is indeed unusual and warrants immediate investigation. While wear and tear are expected over time, this mileage is too low for typical component failure. This could indicate a manufacturing defect or an early failure of a specific component.

Possible Causes:

1. Broken or Weakened Coil Springs: The most common cause of sagging is a broken or fatigued coil spring. Even a small crack can cause the spring to lose its tension and allow the vehicle to sit lower. Given the low mileage, this would likely be a defect.
2. Worn Shock Absorbers: While shocks primarily control damping (bounciness) and don't directly support vehicle weight, severely worn shocks can contribute to a 'squatting' appearance, especially under load, as they can't properly manage the spring's movement. However, they typically don't cause a static sag on their own.
3. Damaged Suspension Bushings: While less likely to cause significant sag, severely deteriorated bushings in the control arms or trailing arms could allow for excessive movement, contributing to a lower stance.
4. Overloading: Consistently carrying excessive weight beyond the vehicle's payload capacity can prematurely wear out suspension components, leading to sagging. However, for a 2023 model, this would have to be extreme and continuous.
5. Manufacturing Defect: Given the low mileage, a defect in a spring or another suspension component is a strong possibility.

What to Check:

• Visual Inspection: Look closely at the rear coil springs for any signs of cracks, breaks, or corrosion. Also, check the shock absorbers for fluid leaks.
• Compare Ride Height: Measure the distance from the ground to the fender lip on both sides of the rear and compare it to the front, and ideally, to another Envision Avenir if possible.

When to See a Shop:

Since your 2023 Buick Envision Avenir is still under warranty, your first step should be to contact your Buick dealership. This issue should be covered under the factory warranty. A professional technician will be able to:

1. Thoroughly inspect the entire rear suspension system for any broken or fatigued components, particularly the coil springs.
2. Check for any signs of damage or premature wear on shocks and bushings.
3. Diagnose the exact cause of the sagging.
4. Perform the necessary repairs or replacements under warranty. Driving with a sagging suspension can negatively impact handling, tire wear, and potentially lead to further damage to other components, so address it promptly.