Skoda Kodiaq Radiator: Specs, Fitment & Common Faults

The Kodiaq's TSI engine shares a water pump housing VW Group has legally admitted used "inferior thermoplastic materials" — a real class-action settlement covers this.

Illustration for editorial purposes

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OEM Part Number: 5Q0121251HD (as quoted in catalogue listings — confirm via VIN) — aftermarket radiators Nissens 606641 / NRF 550329

Accuracy note: Covers the Skoda Kodiaq (2016-) 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 606641 (196 x 186 x 26 mm auxiliary radiator, brazed aluminium with plastic tanks, 2.0 TDI 4x4 190, RS Bi-TDI and RS TSI); NRF 550329; Van Wezel 58012710; Hella 8MK 366 308-081; Bogap A4210320; Hart 667 056
Core sizes & variants	This is the small additional radiator mounted beside the main cooling pack on the higher-output 4x4 Kodiaqs, shared with the Tiguan, Tarraco, Karoq and Q3.
Genuine (OE) numbers quoted	5Q0121251HD
Fitment notes	20 mm inlet and outlet, supplied with gaskets and seals. The main radiator should be ordered against the VIN.

Accuracy note: genuinely worth knowing: radiator core size and construction can differ between petrol and diesel Kodiaq 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.

Confirmed: A Genuinely Serious, Class-Action-Level Design Flaw on TSI Engines — Skoda Kodiaq Radiator

If your car has a TSI turbo petrol engine, this is genuinely the single most important thing to know before anything else on this page. The water pump and thermostat are combined into one integrated plastic housing, and this plastic becomes brittle and develops hairline cracks after thousands of ordinary heat cycles — leading to a coolant leak that's often difficult to spot at first. This isn't a minor manufacturing quirk: VW Group (Skoda's parent company) has confirmed through legal documents that "inferior thermoplastic materials were used" in these water pump components, and the issue has been the subject of multiple class-action lawsuits.

What the settlement genuinely offers: a Technical Service Bulletin extends the warranty on this specific part to 8 years/80,000 miles, and the class-action settlement goes further still — up to 10 years/100,000 miles warranty, reimbursement of qualifying repairs, and reimbursement for consequential damage if the leak went undiagnosed long enough to damage the turbocharger or EGR system.

Separately, if you've already replaced the water pump, cambelt, and thermostat and are still losing coolant with no visible leak anywhere, it's genuinely worth checking the EGR cooler specifically — coolant can leak through a failing EGR cooler with no outward signs at all, since it flows internally into the exhaust rather than dripping visibly. This is often only confirmable by removing the exhaust downpipe and checking for coolant residue.

Skoda Kodiaq Radiator: The Part That Keeps Everything Else From Cooking

This isn't a part anyone gets excited about, but on the Skoda Kodiaq, 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.

Skoda Kodiaq Radiator: Watch: Replacing It

🎬 Watch: Volkswagen Tiguan Radiator Replacement DIY (2018-2024 VW MQB Tiguan 2.0t) (sister (vw tiguan mk2))

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Kodiaq shares Tiguan Mk2 platform; nothing Kodiaq-specific.

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.

Skoda Kodiaq Radiator: What It Does

Keeping the Skoda Kodiaq'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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Skoda Kodiaq 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 Skoda Radiator

The same part, covered across other Skoda models.