2015-2017 Audi S8 & A8 Sport Rear Bumper: A Guide to S8 Plus Diffusers and Parking Sensors
This guide clarifies the critical differences between S8 and S8 Plus bumpers, explains how to inspect a used assembly, and details the integrated parking sensor systems.
- The rear bumper cover for the S8 and S8 Plus is the same, but the lower valance/diffuser is different and not interchangeable without other parts.
- Before buying a used bumper, verify it has the correct cutouts for your car's parking sensor configuration.
- Always inspect a used bumper for cracks near the mounting tabs, as this damage can prevent proper alignment.
- A used OEM bumper is highly recommended over a new aftermarket one to ensure perfect fitment on a precision vehicle like the S8.
Symptoms of a Damaged Rear Bumper
Since a bumper's primary failure is physical damage, symptoms are almost always visual. However, this damage can range from minor cosmetic issues to problems that compromise vehicle safety and functionality.
- Cosmetic Damage: Scuffs, scratches, and paint chips are common. Deeper gouges or cracks in the plastic bumper cover may require professional repair and repainting.
- Structural Damage: A visible dent, deformation, or misalignment of the bumper cover often indicates that the underlying reinforcement bar is bent. A compromised reinforcement bar will not absorb impact correctly in a future collision and should always be replaced.
- Broken Mounting Tabs: The bumper cover attaches to the vehicle's body with a series of plastic tabs and clips. A minor impact can break these tabs, causing the bumper to sag, fit poorly, or have uneven panel gaps with the quarter panels and trunk.
- Parking Assist Malfunctions: A long, continuous beep when you shift into reverse, accompanied by a flashing light on the parking assist button, indicates a fault in the system. This is often caused by an impact that has damaged one or more of the ultrasonic sensors housed within the bumper, or its wiring.
- Camera System Failure: On models equipped with a 360-degree camera system, a flaky or dark image from the rear camera can sometimes be traced to damaged wiring in the bumper area or a loose connection at the control module in the trunk.
Key Differences: S8 vs. S8 Plus Bumpers
While the main bumper cover is often the same across the S8 and S8 Plus, the lower valance (diffuser) and exhaust configuration are different. This is a critical point for buyers, as the parts are not directly interchangeable without swapping multiple components.
- Standard S8: Features a sporty but less aggressive lower valance with quad-oval exhaust tips.
- S8 Plus: The "Plus" model was distinguished by more aggressive styling. It often includes a unique gloss black or carbon fiber rear diffuser and a sport exhaust system.
Warning: A bumper assembly from a standard S8 will NOT be a direct fit on an S8 Plus if you intend to keep the Plus-specific diffuser and exhaust trim. The main cover (part number 4H0-807-067-G-GRU) fits both, but the lower valance is the key difference. Always confirm the part numbers of the lower trim before purchasing.
Buying a Used 2015-2017 S8 Rear Bumper Assembly
For a high-end vehicle like the S8, a used OEM bumper is almost always a better choice than a new aftermarket part. OEM parts guarantee correct fitment, proper material thickness, and alignment with body lines, which is often a problem with cheaper aftermarket copies.
Physical Inspection Checklist
- Check All Mounting Points: Carefully inspect the top and side edges where the bumper mounts to the quarter panels. Look for broken, cracked, or repaired tabs. A bumper with compromised mounting tabs will never align correctly.
- Look for Hidden Cracks: Small impacts can cause hairline cracks, especially around sensor holes or license plate mounts. Flex the bumper slightly to reveal any hidden damage.
- Inspect for Previous Repairs: Look on the unpainted backside of the bumper for signs of plastic welding or heavy body filler. These repairs may not last and can cause paint to bubble or crack later.
- Verify Sensor Holes: Ensure the bumper has the correct number and placement of holes for your vehicle's parking sensor package. Base models may have fewer sensors than fully-optioned ones.
- Get the Reinforcement Bar: If possible, purchase the bumper cover and the metal reinforcement bar (4H0-807-309-D) together. Inspect the bar for any signs of bending, kinking, or rust. A bent bar is a serious safety compromise.
Known Issues, Recalls, and TSBs
As of mid-2024, there are no specific recalls or Technical Service Bulletins (TSBs) from the NHTSA for the rear bumper assembly itself on the 2015-2017 Audi S8. However, owners frequently report issues with the integrated parking sensors.
Parking Sensor Faults
A common issue is the failure of one or more parking sensors, triggering a system error. This can be caused by moisture intrusion, wiring corrosion, or minor impact damage.
Pro Tip: You can diagnose a faulty sensor without special tools. With the ignition on and the car in reverse (and the parking brake on for safety), put your ear very close to each sensor. A healthy sensor will emit a faint, rapid clicking or ticking sound. The sensor that is silent is the one that has failed.
The parking aid control module, located in the trunk, can also fail, but this is less common than a sensor or wiring issue.
Replacement Overview and Difficulty
Replacing the rear bumper assembly is a moderately difficult job that is feasible for an experienced DIYer. Patience is required to avoid scratching the paint on the rear quarter panels.
- Difficulty Rating: 3 out of 5
- Estimated Time: 2-3 hours for removal and installation (not including paint).
- Tools Required: Torx bit set (T-25), socket set with extensions, trim removal tools, and a soft blanket to place the bumper on.
High-Level Steps:
- Open the trunk and remove the side trim panels to access the bolts behind the tail lights.
- Remove the tail light assemblies.
- Remove the Torx screws in each rear wheel well that secure the sides of the bumper.
- Remove the screws along the bottom edge of the bumper.
- With a helper, carefully pull the sides of the bumper outward to release them from the guide clips on the quarter panels.
- Slide the bumper straight back. Do not pull it all the way off yet.
- Disconnect the main electrical harness for the parking sensors and any other electronics.
- Transfer the parking sensors, wiring harness, and any brackets from the old bumper to the new one before installation.
Cost Comparison
Prices for a luxury performance car like the S8 can be high, making a quality used part an attractive option. Note that all bumper covers, new or used, will require professional painting, which can add $500-$800+ to the total cost.
| Part Type | Estimated Cost Range |
|---|---|
| New OEM (Dealer) | $3,000 - $4,500+ (for a complete assembly) |
| New Aftermarket | $300 - $600 (Cover only, fitment may be poor) |
| Used OEM (Recycled) | $700 - $1,800 (for a good condition complete assembly) |
| Shop Labor (Install & Paint) | $800 - $1,500 |
OEM Part Numbers
When searching for parts, use these verified OEM numbers. The "GRU" suffix indicates the part comes primed and ready for paint.
| Part Name | Part Number | Notes |
|---|---|---|
| Bumper Cover | 4H0-807-067-G-GRU | Fits S8, S8 Plus, and A8 with Sport Package. |
| Impact Bar | 4H0-807-309-D | The metal reinforcement beam. |
| Lower Valance / Spoiler | 4H0-807-521-P-GRU | Example for S8/S8 Plus with black moldings. |
| Lower Valance / Spoiler | 4H0-807-521-G-GRU | Example for S8/S8 Plus. |
| Bumper Guide Bracket | 4H0-807-453-D | Side bracket that holds the cover to the body. |
Frequently Asked Questions (FAQ)
Will a rear bumper from a standard Audi A8 fit my S8?
No, a bumper from a standard A8 (part number ending in E-GRU) will not fit properly. However, a bumper from an A8 equipped with the optional "Sport Package" is physically the same as the S8 bumper cover and can be used, though the lower valance may differ.
Do I need to paint a used bumper?
Almost certainly, yes. Finding a used bumper in the exact color code and in flawless, ready-to-install condition is extremely rare. Expect to have any used bumper professionally prepped and painted to match your vehicle perfectly.
Can I reuse my old parking sensors?
Yes, as long as they are not physically damaged and are functioning correctly. The sensors and the wiring harness can be carefully unclipped from the old bumper and transferred to the replacement bumper.
Do I need to calibrate the parking sensors after replacement?
Generally, if you are simply swapping the sensors to a new bumper, no calibration is needed. The system is typically plug-and-play. However, if you replace the parking assist control module or if the system continues to show errors, a diagnostic scan and potential calibration by a qualified technician may be necessary.
Technical Specifications
OEM Part Numbers: 4H0807067G 4H0807067GGRU 4H0807309D 4H0807511 4H0807521GGRU 4H0807521P 4H0807521PGRU
The assembly is a multi-piece design consisting of a flexible plastic outer cover (fascia), a metal impact reinforcement bar, energy absorbers, and a lower valance/diffuser. It integrates cutouts for parking sensors and exhaust tips.
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 S8:
- Symptoms of a Damaged Rear Bumper
- Key Differences: S8 vs. S8 Plus Bumpers
- Buying a Used 2015-2017 S8 Rear Bumper Assembly
- Physical Inspection Checklist
- Known Issues, Recalls, and TSBs
- Parking Sensor Faults
- Replacement Overview and Difficulty
- Cost Comparison
- OEM Part Numbers
- Frequently Asked Questions (FAQ)
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