Peugeot 308 Cabin Air Filter: Intervals, Fitment & Warning Signs

Confirmed by a dealer as a design flaw: blocked scuttle drains under the wipers can flood the driver's footwell through the filter housing — plus a genuine free DIY fix.

Illustration for editorial purposes

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OEM Part Number: confirm via VIN — cabin air filter (aftermarket) Mann CU26014-2 / Mahle LA138

Accuracy note: Covers the Peugeot 308 (T9 2013-2021) as listed in the UK aftermarket catalogues. A cabin filter is a cheap part, but it is bought by number, and the number depends on whether your car was built with a standard particulate filter or an activated-carbon one, as well as on trim and build date. The references below are aftermarket catalogue listings for this generation, grouped by brand; the carmaker's own number is not quoted in those listings, so check the genuine filter against your VIN if you want a guaranteed match. Carbon versions carry their own numbers and are listed separately.

Cabin filter, standard (aftermarket)	Mann CU26014-2, Mahle LA138, Bosch 1987435062, Febi 44847
Activated-carbon version (aftermarket)	Mann CUK 26 014-2, Mahle LAK 138, Bosch 0 986 628 647
Genuine (OE) number	Not quoted in the catalogue listings — the fitted filter varies by trim and build date, so order the genuine one against your VIN
Fitment notes	Standard and carbon filters have different numbers, and the right size depends on trim and build date. Check which type your car was built with before ordering.

A Genuine, Well-Documented Cause of Footwell Flooding: Blocked Scuttle Drains — Peugeot 308 Cabin Air Filter

If you've found water pooling in the driver's footwell, particularly after heavy rain, this is genuinely worth checking directly before assuming a coolant leak or heater matrix fault: the scuttle drain holes underneath the windscreen wipers, which are meant to channel rainwater away from the cabin filter housing and out through the wheel arches, are a well-documented blockage point on this platform. When they clog with leaves and debris, water backs up and finds its way through the cabin filter housing itself and into the footwell — in one documented case, a dealer confirmed this directly, cleared the drains, physically enlarged the drain holes to reduce future blockage, and referred the fault back to Peugeot UK as a design flaw. In more severe, prolonged cases, standing water in this area has been reported to damage the heater fan's electronic resistance board, turning what starts as a simple blockage into a genuinely more expensive electrical repair if left unaddressed.

A genuinely useful, free DIY fix worth trying first: the scuttle drains can be accessed and cleared without professional help — removing the wiper arms and the plastic scuttle panel trim reveals the drain area, and a coat hanger combined with a toothbrush has been used successfully by several owners to clear years of accumulated grime and leaves from the drain holes. Doing this proactively once a year, particularly before autumn, is a genuinely sensible preventive habit given how disruptive and potentially damaging a full blockage can become.

Worth checking directly if you're also noticing a musty smell alongside any dampness: water sitting in this area for extended periods, even without a full footwell flood, can be enough to introduce a persistent musty smell through the vents — worth ruling out blocked scuttle drains specifically, not just the filter itself, if a fresh filter doesn't fully resolve the smell.

Peugeot 308 Cabin Air Filter: Easy to Forget, Easy to Fix

This is one of the few parts on the Peugeot 308 that has zero effect on how the car actually drives — its whole job is air quality inside the cabin, which is exactly why it's so easy to let slide for years.

Peugeot 308 Cabin Air Filter: Watch: Replacing It

🎬 Watch: Peugeot 308 T9 replace cabin filter

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Peugeot 308 Cabin Air Filter reference plate

Before you buy: filter size and whether your car uses a standard or activated-carbon filter varies by trim. Always confirm against your VIN before ordering.

Peugeot 308 Cabin Air Filter: What It Does

Air entering the Peugeot 308's ventilation system passes through the cabin filter first, which traps dust and pollen, and on activated-carbon versions, some airborne odours too. It's entirely separate from the engine air filter — a different part doing a different job for the combustion process, not the cabin.

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Peugeot 308 Cabin Air Filter: Warning Signs, DIY Difficulty & Aftermarket Advice

These are the same regardless of make or model — see our full Cabin Air Filter Guide for signs it needs changing, confirming fitment against your VIN, and choosing standard, carbon, or HEPA media.

More Peugeot Cabin Air Filter

The same part, covered across other Peugeot models.