Audi Q2 Radiator: Specs, Fitment & Common Faults

On the Q2, related Audi models have genuinely had confirmed water pump recalls, with problems documented occurring between 30,000 and 70,000 miles.

Illustration for editorial purposes

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OEM Part Number: 5Q0121251EC (as quoted in catalogue listings — confirm via VIN) — aftermarket radiators Nissens 65317 / Valeo 735557

Accuracy note: Covers the Audi Q2 (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 65317 (650 x 322 x 23 mm, aluminium core with plastic tanks, mechanically jointed fins; the standard MQB main radiator for the 1.0 TFSI, 1.4/1.5 TFSI and 1.6 TDI Q2, matched to the genuine 5Q0121251EC number); Valeo 735557; NRF 58438; Mahle CR 2057 000S; Van Wezel 58002340; Hella 8MK 366 301-711; Prasco AD324R003
Core sizes & variants	The main radiator uses a 650 mm core at 322 mm high and 23 mm deep, shared with the Mk3 A3 and Golf VII on the same platform, and covers petrol and diesel alike; turbocharged engines with a water-cooled intercooler also carry the narrow 115 mm auxiliary radiator mounted alongside it, and both can fail independently. The 2.0 TFSI/TDI quattro Q2 uses a thicker main radiator and a different auxiliary unit, so the engine code should be checked before ordering.
Genuine (OE) numbers quoted	5Q0121251EC (main radiator); 5Q0121251EL (auxiliary radiator)
Fitment notes	Both main-radiator connections are 32.5 mm; the auxiliary unit has 22 mm quick-fit (QF) connections. Nissens units are supplied with seals; the Q2 fit of the main radiator is by OE number, so confirm against the VIN.

Accuracy note: genuinely worth knowing: coolant capacity and radiator sizing on the Q2 tend to track engine displacement and power output closely — a part correct for a smaller-engined version of the same model can undersize the cooling for a larger-engined one.

Audi Q2 Radiator: The Part That Keeps Everything Else From Cooking

Unglamorous as it is, the Audi Q2's cooling system sits behind nearly every serious engine failure that isn't just ordinary wear — and one that went unaddressed for too long. Noticing early warning signs here is a small cost against a potentially very large one.

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.

Audi Q2 Radiator: What It Does

On the Audi Q2, engine coolant sheds its heat into the passing air via the radiator, which is what keeps engine temperature in a safe working range. On automatics, it frequently pulls double duty cooling the transmission fluid through its own internal circuit — a detail that makes getting the exact part number right especially important.

Audi Q2 Radiator: Watch: Replacing It

🎬 Watch: 2015 Audi A3 Premium Radiator Replacement (sister (audi a3 8v))

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No Q2 video found in English or German; A3 8V shares the MQB front end

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A Genuinely Useful Piece of Context Worth Knowing About Water Pump Issues — Audi Q2 Radiator

If you're facing a coolant leak or overheating concern, this is genuinely worth knowing: related Audi models have had confirmed recalls addressing water pump issues that could cause coolant to leak from the pump housing, with problems on this platform documented occurring anywhere from 30,000 to 70,000 miles.

A genuinely useful, real diagnostic technique worth trying: with the engine cold, removing the coolant bottle cap and having someone rev the engine while you watch the return hose is a simple way to confirm the water pump is genuinely circulating coolant properly.

It's also genuinely worth knowing an important clarification: genuine overheating caused directly by a failed water pump is actually quite rare, more often stemming from warped cylinder heads or a weakened head gasket left over from a previous overheating event.

Audi Q2 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 Audi Radiator

The same part, covered across other Audi models.