Related Products
Radiator Cap - Audi (8B3-121-321)
2019-2026 Audi - 8B3-121-321
- MSRP: $24.94
- Discount: $7.92 (31.8% off)
- Sale Price: $17.02
- MSRP: $24.94
Review Fitment & Product Details
Details
- Brand:
- SKU:
8B3-121-321
- Other Names:
Radiator Cap, Reservoir Cap
- Description:
Genuine Audi Radiator Cap 8B3-121-321. This original equipment component moves heat out of the engine and charge air circuits, and because modern Audi engines run tight thermal windows, a partial loss of cooling capacity shows up as performance and economy loss before it shows as overheating. It is supplied through the Audi dealer parts network and matches the component installed at the factory. Use the fitment guide or contact our parts team to confirm the correct application.
- Notes: Included with reservoir assembly.
- Replaces:
4ke121321a
California Proposition 65
WARNING: Cancer and reproductive harm - www.P65Warnings.ca.gov Pricing is valid online only and may vary in your local store
Vehicle Fitment
Vehicle Fitment
| Year | Make | Model | Body & Trim | Engine & Transmission |
|---|
Key Product Information
Additional Information
| SYMPTOMS | Typical failure symptoms reported on vehicles fitted with 8B3-121-321: rising coolant temperature, low coolant level warnings, sweet smelling steam, a heater that blows cold, or visible pink or clear residue on hoses and joints. Symptoms vary by model year and option content, so confirm fitment before ordering. |
| TROUBLESHOOTING | Verify the fault before ordering 8B3-121-321: pressure test the system cold to expose seeping joints, then verify thermostat opening behavior against live coolant temperature data before replacing pumps or radiators. Document the readings before and after the repair so the fix can be verified. |
| INSTALLATION | Installing 8B3-121-321 correctly calls for a proper vacuum or bleed fill so no air pocket remains, since trapped air in these systems causes false overheating and heater performance complaints. Torque values differ by model and production date, so consult the factory literature. |
| MAINTENANCE | Keeping 8B3-121-321 in service means using the correct Audi coolant specification, never mixing coolant types, and checking hose condition and clamp tension at each service. A short inspection at each service keeps small issues from becoming large ones. |
| GENERAL_NOTES | Before purchasing 8B3-121-321, note that coolant color and specification vary by production era, and mixing incompatible types causes gelling that clogs the heater core and radiator. Aftermarket equivalents often differ in material and tolerance, which shows up during installation. |
| REPLACEMENTS | Order these together with 8B3-121-321: hose clamps, O-rings, thermostat housings, and coolant are renewed at the same time because access is shared and old seals rarely reseal. Confirm the related part numbers against the vehicle identification number. |
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