Mini Cooper Radiator: Specs, Fitment & Common Faults

A genuinely important design limitation: these cars have no temperature gauge, only a warning light that illuminates after the engine is already dangerously hot — plus a money-saving finding about doing the thermostat housing, link pipe, and water pump together.

Illustration for editorial purposes

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OEM Part Number: 17118645778 (as quoted in catalogue listings — confirm via VIN) — aftermarket radiators Nissens 606385 / Mahle CR 2748 000P

Accuracy note: Covers the Mini Cooper (F56 2014-) as listed in the UK aftermarket catalogues. Radiators are sold by engine, gearbox and air-conditioning fitment, and one model usually has two or three different cores — a thicker core for diesels and automatics, a thinner one for small petrols — with different hose positions, so a radiator for the wrong engine will not connect up. The references below are UK aftermarket listings whose fitment lists name this generation, labelled by brand with the core size in mm; genuine numbers are those quoted against the listing. Check your engine code and whether the car has air conditioning against your VIN, and replace the coolant and bleed the system after fitting.

Radiators (aftermarket)	Nissens 606385 (680 x 351 x 22 mm, aluminium soldered core, plastic tanks, One, One First and Cooper with the B38 1.5 three-cylinder petrol); NRF 550414; Hella 8MK 366 304-551; AKS Dasis 050128N. Nissens 606391 (682 x 299 x 22 mm, aluminium soldered core, plastic tanks, One D and Cooper D with the B37 1.5 diesel and Cooper SD with the B47 2.0 diesel); Mahle CR 2748 000P; NRF 550362; Hella 8MK 366 304-521; Van Wezel 06012745
Core sizes & variants	The 1.5 petrol Cooper and One take a taller 351 mm core; the diesels (Cooper D, One D, Cooper SD) take a shallower 299 mm core. The Cooper S and JCW (B48 2.0 petrol) are not on either fit list and use a different radiator. The listings cover pre-facelift cars to 2017; later LCI cars should be checked against the VIN.
Genuine (OE) numbers quoted	17118645778 (petrol unit); 17118586321 (diesel unit)
Fitment notes	Inlet and outlet are 32.5 mm on both; the petrol unit is supplied with seals.

Accuracy note: genuinely worth knowing: radiator core size and construction can differ between petrol and diesel Cooper engines, and again between manual and automatic gearboxes where the automatic needs an integrated oil cooler circuit — confirm your exact engine code and transmission before ordering.

Mini Cooper Radiator: The Part That Keeps Everything Else From Cooking

This isn't a part anyone gets excited about, but on the Mini Cooper, overlooked cooling problems are responsible for most serious engine failures that aren't simple wear-and-tear. Catching the early symptoms is about the cheapest insurance available against a major bill later.

Before you buy: radiator size and design vary significantly by engine size, transmission type, and whether your car has air conditioning. Always confirm against your VIN before ordering.

Mini Cooper Radiator: What It Does

Keeping the Mini Cooper's engine temperature within safe limits comes down to the radiator's job of transferring heat from the coolant into the surrounding air. Automatic-gearbox versions often build in a second circuit for transmission fluid cooling too, which is exactly why fitting the wrong part number can cause two problems, not one.

Mini Cooper Radiator: Watch: Replacing It

🎬 Watch: How to Fit A Radiator, Air Conditioning and Intercooler Mini F56 John Cooper Works Part 4.

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F56 JCW rebuild series; the radiator goes in with the condenser and intercooler.

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A Genuinely Important Design Limitation Worth Knowing — Mini Cooper Radiator

This is genuinely important to understand about how these cars display temperature: there's no conventional temperature gauge at all, only a warning light — meaning by the time this light actually illuminates, the engine has typically already reached a genuinely damaging temperature, rather than giving you the kind of early, gradual warning a traditional gauge would provide. It's worth taking any overheating warning extremely seriously and stopping promptly rather than continuing to drive to see how bad it gets, given this design doesn't give you the early visibility a gauge would.

A genuinely useful, money-saving finding worth knowing if the thermostat housing needs replacing: the plastic thermostat housing and a separate plastic link pipe at the rear of the engine both tend to degrade with age and heat at a broadly similar rate, and accessing either one requires removing the water pump regardless. It's genuinely worth replacing all three together as a preventative measure while you already have the necessary access, rather than paying for the same labour a second time when the remaining part inevitably fails later — worth knowing that a garage may not always proactively suggest this more efficient, combined approach.

It's also genuinely worth knowing that Cooper S models specifically have a separate, additional auxiliary water pump, whose job is to continue circulating coolant for a period after the engine has been switched off, specifically to help cool the turbocharger. This separate pump is a genuine, additional component many owners aren't aware exists, and it can develop its own faults independently of the main water pump.

Mini Cooper Radiator: Faults, DIY Difficulty & Aftermarket Advice

These are the same regardless of make or model — see our full Radiator Guide for the three common failure modes, confirming fitment against your VIN, and OEM vs aftermarket guidance.

More Mini Radiator

The same part, covered across other Mini models.