CSF 8355 Auxiliary Radiator for 16-18 BMW M2/16-21 BMW 340i/440i/M240i N55/B58

Vehicle Fitment

• 2016-2018 BMW M2 3.0L Turbo I6 (F87 -- N55)
• 2016-2018 BMW 340i / 340i xDrive 3.0L Turbo I6 (F30 -- B58)
• 2017-2020 BMW 440i / 440i xDrive 3.0L Turbo I6 (F32 Coupe -- B58)
• 2017-2020 BMW 440i / 440i xDrive Gran Coupe 3.0L Turbo I6 (F36 -- B58)
• 2017-2020 BMW 440i Convertible 3.0L Turbo I6 (F33 -- B58)
• 2017-2020 BMW M240i / M240i xDrive 3.0L Turbo I6 (F22 -- B58)
• 2016-2019 BMW M140i 3.0L Turbo I6 (F20 -- B58, Non-US Market)

Fitment Notes

• Does NOT fit F87 M2 Competition (S55) -- use CSF #8258
• F87 M2 (N55): one unit on left side only -- right side uses CSF #8104 oil cooler
• F3X/F2X B58 models: most use two auxiliary radiators (left and right)
• Drop-in replacement for BMW OE 17-11-8-625-447
• Also replaces 17-11-7-628-057 and 17-11-7-600-697 with correct brackets
• Minor air duct trimming may be needed on non-M Sport equipped vehicles
• Mounting brackets sold separately
• Sold individually

Features

• High-performance upgrade over OE plastic auxiliary radiator
• 2-row 42mm core with CSF B-Tube technology
• 5mm multi-louvered fins maximize heat exchange surface area
• TIG-welded aluminum tanks replace OE plastic
• Enlarged core and increased fluid volume vs. OE
• Multi-fit design -- mounts on left or right side
• OEM quick-connect fittings -- no modification required
• Reduces coolant temps and extends heat soak threshold

Specifications

• Part Number: 8355
• Brand: CSF
• Type: High-Performance Auxiliary Radiator
• Core: 2-Row, 42mm, B-Tube
• Fin: 5mm Multi-Louvered
• Tank Material: TIG-Welded Aluminum
• Connections: OEM Quick-Connect
• OE Reference: BMW 17-11-8-625-447

Included Components

• CSF high-performance auxiliary radiator (1)

Product Description

The CSF 8355 is a high-performance auxiliary radiator designed for the BMW F87 M2 (N55), F3X 340i/440i, and F2X M240i/M140i platforms equipped with N55 and Gen 1 B58 turbocharged inline-six engines. This unit is a direct drop-in replacement for BMW OE part 17-11-8-625-447, mounting in the factory location using OEM quick-connect fittings with no modifications required. The 2-row 42mm aluminum core features CSF's exclusive B-Tube technology and 5mm multi-louvered fins for significantly increased heat exchange surface area over the OE unit. TIG-welded aluminum tanks replace the factory plastic tanks for improved strength and increased fluid volume. An integrated frame design eliminates the need for the separate OE cradle bracket. Working alongside the primary radiator, the CSF auxiliary radiator reduces coolant temperatures and extends the heat soak threshold during aggressive driving and track sessions. Does not fit the F87 M2 Competition (S55 engine). F87 M2 (N55) uses a single unit on the left side, while F3X/F2X applications typically use two. Verify your vehicle's auxiliary radiator configuration by VIN before ordering. Mounting brackets sold separately. Sold individually.