do88 Performance Radiator – BMW F-Series B58 / B48 (M240i / 340i / 440i / 230i / 330i / 430i)

OVERVIEW

The factory radiator in the F-series 2, 3 and 4 Series is sized for stock power and street driving. Add a tune, track days or summer heat and coolant temperatures climb, and the ECU starts pulling timing. The do88 WC-420 is a direct-fit aluminum replacement for the B58 M240i, 340i and 440i and the B46/B48 230i, 330i and 430i.

It has 66 percent more core volume than the factory radiator: a 48 mm two-row core with 120 percent more cooling surface and a triple-pass layout that keeps coolant in the core longer. It bolts in using the factory mounting points and hoses, with no cutting or modification.

SPECS

• All-aluminum radiator, direct replacement for OE
• 48 mm, two-row core; 66 percent more core volume than OE
• 120 percent more cooling surface area
• Triple-pass coolant flow
• Uses OE mounting points and hoses — no modifications required
• Replaces OE 17118741830 and 17118625431

PARTS INCLUDED

• 1 × do88 aluminum radiator
• 2 × brackets
• 5 × screws and 1 × nut (for cars with an engine oil cooler)
• 2 × silicone caps

TECH RESOURCES

• Required extras: BMW-approved coolant to refill the system; a vacuum-fill tool or diagnostic tool to run the electric water pump bleed routine is recommended.
• Installation instructions (do88): WC-420 F-series radiator installation instructions (PDF)
• Installation notes: drain the coolant, remove the front bumper support parts and the OE radiator, transfer the fan shroud and sensors, and fit the do88 radiator with the supplied brackets. Cars with an engine oil cooler use the supplied screws and nut; cap unused ports with the silicone caps.
• Bleeding: follow the BMW bleed procedure for the electric water pump and recheck the level after the first heat cycles.
• Price is for the item only; labor is not included.

PART NUMBER

• WC-420 — do88 Performance Radiator, BMW F-Series B58 / B48

VEHICLE APPLICATIONS