Radiator – 4F0 121 251 AC
Radiator for the Audi A6 (C6) platform, OE number 4F0 121 251 AC. Main group 121 sub-group 251 identifies this as a radiator. Revision index AC. Cooling capacity and mounting differ between engine variants on the same platform — confirm against your engine code before ordering.
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Technical specifications
| Part Number | 4F0 121 251 AC |
| SKU | AUD-4F0121251AC |
| Brand | |
| Category | Radiators |
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3–5 business days. Free on orders over $150.
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Order before 2 PM for next business day delivery.
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Return unused parts within 30 days for a full refund.
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Customer reviews
Verified feedback from Audi owners and independent workshops.
4.2
5 reviews
Aisha Bauer
July 21, 2026
Solved my overheating
Bought for a 2022 A6 C8. The core is thicker than the unit it replaced and the fin density is noticeably higher. All the mounting points and hose stubs lined up without any persuasion. Result is the gauge sits dead centre now even in traffic on a hot day.
Hannah Marchetti
July 7, 2026
Straight swap
Cross-referenced the OE number against my 2018 Q3 8U before ordering. The plastic feels substantial rather than the brittle stuff that cracks at the neck. The transmission cooler lines threaded straight in with no adapters. Result is no more creeping temperature when towing. No complaints at all.
Rajesh Bergmann
March 8, 2026
Holds pressure beautifully
Ordered this for my Q3 8U after the original gave up at 82k. The transmission cooler lines threaded straight in with no adapters. The plastic feels substantial rather than the brittle stuff that cracks at the neck. Result is the gauge sits dead centre now even in traffic on a hot day. Exactly what I needed.
Amara Larsen
December 17, 2025
Works well, packaging was thin
My A3 8P needed this doing at 88k miles. Front end off, old one out, this one in over a long Saturday. I pressure tested it to 1.4 bar before fitting and it held without a drop. On balance the gauge sits dead centre now even in traffic on a hot day. Worth buying, just go in with your eyes open.
Martin Vance
August 5, 2025
Better core than the original
Fitted to my 2023 Q7 4M. All the mounting points and hose stubs lined up without any persuasion. The plastic feels substantial rather than the brittle stuff that cracks at the neck. Result is intake temps dropped noticeably on a long motorway pull.