2017-2019 Audi Q7 & 2019 Q8 Front Radiator Support (Lock Carrier) Guide
This guide covers the essential information for diagnosing, replacing, and purchasing a used front radiator support for the Audi Q7 and Q8.
- This part is a critical structural component called a radiator support or lock carrier, not just a cosmetic panel.
- Failure is almost always due to a front-end collision; symptoms include poor panel gaps, hood latch issues, and visible damage.
- When buying used, meticulously check for hairline cracks and warping, as they will prevent proper alignment.
- Replacement is a complex, high-difficulty job (4/5) best left to professionals as it requires removing the entire front end.
Symptoms of a Damaged Radiator Support
Since the radiator support is a structural part, its failure is almost always caused by a front-end impact. Symptoms are typically visual and related to the alignment of surrounding parts.
- Visible Cracks or Deformation: The most obvious sign is visible damage to the support itself, which is often made of plastic or a composite material. This requires looking behind the front bumper grille.
- Poor Panel Gaps: If the gaps between the hood, fenders, and bumper cover are uneven, it can indicate that the underlying support structure is bent or broken.
- Difficulty Latching or Opening the Hood: The hood latch mechanism is mounted to the radiator support. If the support is misaligned, the hood may not close, latch, or release properly.
- Cooling System Leaks or Overheating: Damage to the support can easily puncture or crack the radiator or A/C condenser it holds, leading to coolant or refrigerant leaks and potential engine overheating.
- Headlight Misalignment: Headlights are bolted to the radiator support. If your headlight beams point in the wrong direction or the housings appear crooked after an impact, the support is likely damaged.
Pro Tip: After even a minor front-end collision, carefully inspect the radiator support for hairline cracks, especially around mounting points for the radiator and headlights. What seems like minor cosmetic damage to the bumper can hide significant structural damage underneath.
Buying a Used Front Radiator Support
Purchasing a used OEM radiator support is a smart way to save money, especially since fitment is critical for this part. Aftermarket versions can have slight variations that lead to frustrating installation issues and poor panel alignment. Here’s what to check before you buy:
- Inspect for Cracks: Carefully examine the entire part, paying close attention to corners, mounting tabs, and the areas where the radiator and condenser sit. Reject any part with visible cracks, no matter how small.
- Check for Warping: Lay the support on a flat surface to check for any twisting or warping. A deformed support will make it impossible to align the hood, fenders, and headlights correctly.
- Verify All Mounting Points: Compare the used part to photos of a new one. Ensure every mounting tab, clip receptacle, and bolt hole is intact and not broken, stripped, or elongated. Damage to these areas is common in a collision.
- Confirm Part Numbers: The primary OEM part number is 4M0805594B, which supersedes the earlier 4M0805594. Ensure the part you are buying matches, as there can be subtle differences between trim levels or model years.
Known Issues, Recalls, and TSBs
While there are no recalls or Technical Service Bulletins (TSBs) specifically for the radiator support itself, several front-end related recalls for the 2017-2019 Audi Q7 and 2019 Audi Q8 are worth noting.
- Steering Shaft Bolt Recall (NHTSA Campaign Number 20V149): A recall was issued for some 2017-2019 Q7 and 2019 Q8 models because a bolt connecting the steering shaft to the steering gear could loosen over time, potentially leading to a loss of steering control. Dealers will inspect and replace the bolt free of charge.
- Front Shock Absorber Fork Recall (NHTSA Campaign Number 19V114): On certain 2019 Q7 and Q8 vehicles, the front shock absorber forks could crack, allowing the shock to loosen and potentially affect steering control.
- Third Row Seat Recall (2017 Q7): On some 2017 Q7s, the third-row seat back could move forward during a frontal collision, increasing injury risk. This is relevant as it relates to front-end collision safety systems.
There are no widespread factory defects reported for the radiator support itself; failures are almost exclusively due to collision damage.
Cost of Replacement
Replacing the radiator support is a labor-intensive job that involves removing the entire front bumper assembly. Costs can vary significantly based on parts chosen and labor rates.
| Part/Service | Estimated Cost |
|---|---|
| New OEM Radiator Support | $490 - $720 |
| New Aftermarket Radiator Support | $190 - $370 |
| Used OEM Radiator Support | $150 - $350 |
| Shop Labor | $550 - $820 |
Note: The labor cost is for replacing the support only. If the radiator, condenser, or other components were also damaged, the total repair cost will be significantly higher. For example, a full radiator replacement can cost between $2,648 and $2,908.
Frequently Asked Questions (FAQ)
Is this part the same for the Audi Q7 and Q8?
Yes, the front radiator support with part number 4M0805594B is listed as fitting the 2017-2019 Audi Q7 and the 2019 Audi Q8. These vehicles are built on the same platform, sharing many structural components.
Can I replace a radiator support myself?
This is an advanced DIY job. It requires removing the front bumper cover, headlights, and disconnecting cooling system components. It also requires careful alignment of all front-end body panels upon reassembly. For most people, this job is best left to a professional body shop. We rate the difficulty as 4 out of 5.
What does "CAPA Certified" mean for an aftermarket part?
CAPA (Certified Automotive Parts Association) is an independent organization that tests and certifies aftermarket parts to ensure they fit, perform, and are as safe as the original OEM parts. If you choose an aftermarket support, a CAPA-certified one is a good choice for better quality and fitment.
Do I need to get my headlights re-aimed after replacement?
Yes. Because the headlights mount directly to the radiator support, replacing it will almost certainly change their alignment. It is essential to have the headlights professionally aimed after the repair to ensure proper visibility and avoid blinding other drivers.
Technical Specifications
OEM Part Numbers: 4M0805594B 4M0805594
Material: Plastic/Composite Position: Front
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 Q7:
- Audi Q8: