Peugeot 308 Radiator: Specs, Fitment & Common Faults

On the 308, which side a coolant leak comes from often tells you whether it's the water pump or thermostat housing — plus why "no puddle" doesn't mean no leak.

Illustration for editorial purposes

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OEM Part Number: 9809141780 (as quoted in catalogue listings — confirm via VIN) — aftermarket radiators Nissens 636042 / Valeo 735555

Accuracy note: Covers the Peugeot 308 (T9 2013-2021) 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 636042 (648 x 408 x 26 mm, without cap, without expansion tank, with gaskets/seals); Nissens 636014 (650 x 433 x 18 mm, without gasket/seal); Valeo 735555 (650 x 433 x 18 mm, for vehicles without oil cooler); NRF 59302 (650 x 408 x 16 mm); NRF 59302A (650 x 408 x 32 mm); NRF 59355 (648 x 408 x 26 mm); Hella 8MK 366 301-731 (648 x 408 x 26 mm, without expansion tank, with gaskets/seals); Hella 8MK 366 301-501 (650 x 408 x 16 mm, without expansion tank, without gasket/seal)
Core sizes & variants	650 mm wide core; 16-18 mm for the 1.2 PureTech petrols, 26 mm for the 1.6 and 2.0 BlueHDi diesels.
Genuine (OE) numbers quoted	9809141780
Fitment notes	Shared with the 3008 II and Citroen C5 Aircross, so there is plenty of aftermarket choice.

Accuracy note: genuinely worth knowing: radiator core size and construction can differ between petrol and diesel 308 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.

A Genuine, Useful Diagnostic Shortcut for RHD Cars — Peugeot 308 Radiator

If you've found a coolant leak and can see roughly which side of the engine bay it's coming from, this is genuinely useful to know on a right-hand-drive UK car: a leak from the driver's side generally points to the water pump, while a leak from the passenger side generally points to the thermostat housing — both are common, well-documented failure points, and knowing which side narrows down the likely cause considerably before a garage even looks at it.

A genuinely important point worth knowing: these leaks don't always produce a visible puddle on the ground. Several owners report a coolant reservoir that empties gradually over days with no pool ever appearing underneath the car — the leak can be fine enough that it simply mists away once the engine reaches full temperature, evaporating before it ever reaches the ground. Don't take "no puddle underneath the car" as proof there's no leak; a steadily dropping coolant level with genuinely no visible pool anywhere is still worth investigating as a likely thermostat housing or water pump seal issue.

It's also worth knowing that both the water pump and thermostat housing have been revised by Peugeot over time — if you're having either replaced, confirming you're getting the current, updated part reference rather than an older superseded version is worth asking about directly.

Peugeot 308 Radiator: The Part That Keeps Everything Else From Cooking

There's nothing exciting about this component, yet on the Peugeot 308, most catastrophic engine failures that aren't simply down to wear trace back to a cooling problem someone ignored too long. Catching it early is cheap; catching it late usually isn't.

Peugeot 308 Radiator: Watch: Replacing It

🎬 Watch: Peugeot 308 radiator replacement without removing bumper T7 (older gen)

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T7 generation; T9 hits were heater matrix and coolant only

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.

Peugeot 308 Radiator: What It Does

The Peugeot 308 radiator's core job is moving heat out of the engine coolant and into the passing air, holding engine temperature within safe limits. Automatic versions frequently add a second internal circuit for transmission fluid cooling, which is exactly why the correct part number carries extra weight on this component.

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Peugeot 308 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 Peugeot Radiator

The same part, covered across other Peugeot models.