Mazda CX-3 Radiator: Specs, Fitment & Common Faults

On the CX-3, the coolant reservoir genuinely differs by turbo vs non-turbo and even build location — always verify against your VIN.

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OEM Part Number: S55215200 (as quoted in catalogue listings — confirm via VIN) — aftermarket radiators Nissens 606117 / Denso DRM44043

Accuracy note: Covers the Mazda CX-3 (2015-) 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 606117 (375 x 578 x 16 mm, aluminium core with plastic tanks, supplied with thermostat and filler cap, 2.0 Skyactiv-G PE); Denso DRM44043; NRF 59250; Ava MZ2291; Van Wezel 27012700; Hella 8MK 366 308-651; Nissens 606109 (375 x 740 x 26 mm, 1.5 Skyactiv-D S5 and 1.8 Skyactiv-D S8); Denso DRM44050
Core sizes & variants	The 2.0 petrol takes a 375 x 578 x 16 mm radiator, while the diesels take a much larger 375 x 740 x 26 mm unit shared with the Mazda 2 1.5 D, so the two are not interchangeable.
Genuine (OE) numbers quoted	PEHH15200 (petrol); S55215200; S55215200A; S55215200B; S55215200D (diesel)
Fitment notes	Both have 33 mm hose connections. The petrol Nissens unit comes with a new thermostat, sealing cap and gaskets fitted, which saves transferring the old ones.

Accuracy note: genuinely worth knowing: Mazda sometimes fits a heavier-duty radiator as standard on CX-3 trims with towing packs or higher-accessory-load options — worth confirming your exact spec rather than assuming the base-model rating applies.

A Genuinely Important Fitment Warning Worth Knowing Before Ordering — Mazda CX-3 Radiator

If you're replacing the coolant reservoir specifically, this is genuinely worth knowing: fitment is considerably more complex than it might first appear, with real differences depending on whether your engine is turbocharged or non-turbo, and even on which factory the car was built in. Always verify against your specific VIN and visually match the part before buying.

A genuinely specific diagnostic detail worth knowing if chasing a subtle thermostat housing leak: rather than an obvious crack across the housing itself, a failing gasket or seal commonly manifests as weeping specifically around one of the housing bolts — worth checking this precise spot closely before assuming the housing itself needs replacing.

It's also worth knowing that a coolant bypass pipe near the thermostat housing on some Mazda diesel engines has been documented deteriorating with age and heat cycles, worth checking if you have an older diesel model experiencing unexplained coolant loss.

Mazda CX-3 Radiator: The Part That Keeps Everything Else From Cooking

This isn't a part anyone gets excited about, but on the Mazda CX-3, 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.

Mazda CX-3 Radiator: Watch: Replacing It

🎬 Watch: How to Replace Radiator 2014-2018 Mazda 3 (sister (mazda 3))

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Nothing on CX-3 or Mazda 2 DJ; Skyactiv-era Mazda 3 layout is the closest found

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.

Mazda CX-3 Radiator: What It Does

Keeping the Mazda CX-3'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.

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Mazda CX-3 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 Mazda Radiator

The same part, covered across other Mazda models.