do88 Performance Radiator – BMW 135i / 335i / Z4 35i (E8x / E9x / E89, N54 / N55)

OVERVIEW

The factory radiator in the N54 and N55 E-series cars uses plastic end tanks, and they're now old enough to crack. The do88 radiator is an all-aluminum replacement with continuous welds and no plastic, and it drops in on the factory mounts.

Core volume is 29 percent larger than stock, with a 40 mm single-row core and multi-louvered fins. Order the version that matches the gearbox: WC-370 for Steptronic or DCT automatics, WC-390 for manuals.

SPECS

• All-aluminum construction with continuous welds — no plastic tanks
• Single-tube core, 1 row, 40 mm thick; multi-louvered 5.0 mm fins
• Core volume: 8,616 cm³ vs 6,701 cm³ OE — about 29 percent larger
• Frontal area: 2,154 cm² vs 2,094 cm² OE
• WC-370 replaces OE 17117547059 (automatic); WC-390 replaces OE 17117558480 (manual)

PARTS INCLUDED

• 1 × do88 aluminum radiator (automatic or manual version)

TECH RESOURCES

• Required extras: BMW-approved coolant to refill and bleed.
• Installation instructions (do88): WC-370 automatic radiator instructions (PDF)
• Installation instructions (do88): WC-390 manual radiator instructions (PDF)
• Installation notes: choose the gearbox version that matches your car — automatic radiators carry the transmission cooler connections. Drain, swap the radiator on the factory mounts, refill and bleed per BMW procedure.
• Price is for the item only; labor is not included.

PART NUMBER

• WC-370 — do88 Radiator, BMW 135i / 335i / Z4 35i N54 / N55, automatic
• WC-390 — do88 Radiator, BMW 135i / 335i / Z4 35i N54 / N55, manual

VEHICLE APPLICATIONS