2019-2025 Audi e-tron & Q8 e-tron Underbody Shield: Noise, Damage, and Replacement Guide
This guide covers the main underbody shield that protects the battery and improves aerodynamics on the all-electric Audi e-tron, Q8 e-tron, and SQ8 e-tron models.
- This underbody shield is critical for protecting the high-voltage battery and maximizing aerodynamic range on all-electric e-tron and Q8 e-tron models.
- The most common failures are from impacts with curbs and road debris, leading to scraping noises, rattling, or a visibly sagging panel.
- When buying a used shield, prioritize the condition of the mounting points; cracks or breaks here will prevent a secure fit.
- This part (OEM #4KL399345B) is for electric models ONLY and will not fit gasoline-powered Audi Q8 vehicles.
Symptoms of a Damaged Underbody Shield
Damage to the underbody shield is most often caused by impacts with road debris, high curbs, speed bumps, or large accumulations of snow and ice. When this panel is damaged, loose, or missing, you may notice one or more of the following symptoms.
- Scraping or Dragging Noises: This is the most obvious sign. A loose or sagging shield will make a scraping sound as it drags on the pavement, especially when going over bumps, dips, or up driveways. 🎬 Watch: Identifying scraping noises caused by loose underbody components
- Rattling or Clunking Sounds: A shield that is loose but not yet dragging may rattle or clunk against the chassis or other underbody components. This noise may be more noticeable at certain speeds as airflow causes the loose panel to vibrate.
- Visible Sagging or Damage: A quick visual inspection may reveal that the shield is hanging lower than it should be, or you might see cracks, holes, or bent sections. The mounting points are a common failure area.
- Excessive Dirt in Underbody Components: If the shield is missing, you might notice an unusual buildup of dirt, grime, or road salt on the components it's meant to protect. This can lead to corrosion on other parts over time.
Known Issues, TSBs, and Recalls
While there are no major recalls specifically for this underbody shield, Audi has issued at least one Technical Service Bulletin (TSB) that may be related to noises from this area.
- TSB #A4024752047920_9: Released on March 8, 2024, for the 2022 Audi e-tron, this bulletin addresses noises coming from the front end and dash panel area while the vehicle is moving. The bulletin specifically mentions "UNDERBODY SHIELDS" as part of its subject. If you experience unexplained rattling, this TSB may guide a technician to the source of the problem. 🎬 See how a loose shield causes strange noises on e-trons
Buying a Used Underbody Shield
Given the high cost of a new OEM shield, a used, recycled part is an excellent value. Because this part is critical for protection and aerodynamics, a high-quality used OEM shield is often a better choice than a cheap, new aftermarket one. Aftermarket shields may use thinner, more brittle plastic and may not fit as precisely, which can compromise protection and potentially create noise or increase aerodynamic drag. When inspecting a used OEM shield, check for the following:
- Check All Mounting Points: This is the most critical inspection. Ensure all the holes where bolts or clips attach are intact and not cracked, broken, or elongated. A shield with a damaged mounting point will never fit securely and will likely cause rattling.
- Look for Cracks and Fractures: Inspect the entire surface of the panel, especially around the edges and any bends. Minor surface scuffs and scratches are normal and purely cosmetic. However, reject any shield with significant cracks or holes, as this compromises its structural integrity and protective capability.
- Check for Warping or Bending: Lay the shield on a flat surface to check for any major warping or bending. A bent shield may be difficult to install and may not sit flush against the underbody, affecting aerodynamics.
- Verify the Part Number: Ensure the part number matches what is required for your vehicle. The primary OEM part number for this shield across all listed models is 4KL399345B.
Replacement Cost & Difficulty
Replacing the underbody shield is a straightforward job that a DIY mechanic with basic tools can typically complete.
| Item | Estimated Cost |
|---|---|
| New OEM Part | $435 - $640 |
| New Aftermarket Part | $150 - $300 |
| Used OEM Part | $175 - $350 |
| Shop Labor | $100 - $200 |
Installation Difficulty: 2/5
The replacement process involves safely lifting the front of the vehicle, removing a series of screws and fasteners, taking down the old panel, and installing the new one. No special calibration is required. The estimated time is about 1 to 1.5 hours.
🎬 Watch: Step-by-step guide to removing an Audi undertray coverPro Tip: When removing the old shield, it's a good idea to purchase a new set of fasteners. The original clips and bolts can become brittle, rusty, or get lost during removal. Having new hardware on hand ensures the new shield can be installed securely.
Frequently Asked Questions (FAQ)
Is this underbody shield the same for the e-tron and the newer Q8 e-tron?
Yes, the OEM part number 4KL399345B is specified for the 2019-2023 Audi e-tron, 2020-2023 e-tron Sportback, and the 2024-2025 Q8 e-tron, Q8 e-tron Sportback, SQ8 e-tron, and SQ8 e-tron Sportback models. This is because the Q8 e-tron is an evolution of the original e-tron, built on the same platform.
Can I drive without the underbody shield?
While the vehicle will operate without it, it is not recommended. Driving without the shield exposes the high-voltage battery, motors, and other critical components to potential damage from road debris and water. It can also negatively impact aerodynamic efficiency, which may slightly reduce your driving range. If your shield is dragging, it's safer to remove it completely as a temporary measure than to let it risk catching on something and causing an accident.
Will a damaged splash shield cause a warning light?
No, a damaged or missing splash shield will not trigger any warning lights on the dashboard. The only symptoms will be physical, such as noise or the panel dragging on the ground.
Does this part fit the gasoline-powered Audi Q8?
No, this is a critical distinction. The part number 4KL399345B and the associated underbody panels are specifically for the all-electric e-tron and Q8 e-tron models. They will not fit the gasoline or diesel-powered Audi Q8.
Helpful Videos
Technical Specifications
OEM Part Numbers: 4KL399345B
Material: Aluminum or composite material.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Audi e-tron:
- Audi e-tron Sportback:
- Audi Q8 e-tron:
- Audi Q8 e-tron Sportback:
- Audi SQ8 e-tron:
- Audi SQ8 e-tron Sportback: