Volvo V40 Spark Plugs: Intervals, Fitment & Warning Signs

On the V40, swapped coil connectors after a plug change have genuinely caused severe misfiring on related models, persisting even after fitting new coils.

Illustration for editorial purposes

OEM Part Numbers

Accuracy note: we weren't able to verify a confident Volvo V40 spark plugs part number at the time of writing. Please confirm the correct part via a Volvo dealer or parts specialist using your VIN.

A Cheap Part That Causes Expensive-Feeling Problems

Worn spark plugs rarely announce themselves clearly — a slightly rougher idle, a bit less punch off the line — symptoms easy to blame on almost anything else in the engine bay. The part itself costs very little, which makes it an easy one to overlook for far longer than it should be.

Before you buy: plug type and gap specification vary by engine size and generation. Always confirm against your VIN before ordering.

What They Do

Spark plugs ignite the compressed fuel-air mixture inside each cylinder, and their condition directly affects combustion efficiency, fuel economy and smooth running. Petrol engines rely entirely on them; diesel engines don't use spark plugs at all, relying on compression instead.

Generations & Spark Plug Count

Diesel variants	Not applicable — diesel engines use compression ignition and have no spark plugs at all
Petrol variants (all trims, T2 to T8 plug-in hybrid)	4 spark plugs — one per cylinder; Volvo's current Drive-E engine family is four-cylinder across every trim, regardless of how the power output badge number might suggest a bigger engine

A Genuinely Useful Piece of Context Worth Knowing About Coil Connectors — Volvo V40 Spark Plugs

If a misfire appears specifically after replacing spark plugs, this is genuinely worth knowing: documented cases on related Volvo models describe adjacent coil connectors being accidentally swapped when reconnecting them after a plug change, causing severe misfiring that persisted even after fitting an entirely new set of coils, only resolved by correctly matching each connector to its proper cylinder.

Worth knowing that a worn spark plug makes its corresponding ignition coil work harder, and documented cases describe this eventually causing a coil pack's wiring to become damaged enough to fuse and melt on one cylinder.

It's also worth knowing a useful diagnostic technique: swapping the coil from a misfiring cylinder to a different one and clearing the codes can help confirm whether the coil itself is genuinely at fault.

Warning Signs, DIY Difficulty & Aftermarket Advice

These are the same regardless of make or model — see our full Spark Plugs Guide for symptoms of worn plugs, why matching your exact plug specification matters, and trusted brands to buy from.

More Volvo Spark Plugs

The same part, covered across other Volvo models.

Volvo V40 Spark Plugs: Intervals, Fitment & Warning Signs

OEM Part Numbers

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A Genuinely Useful Piece of Context Worth Knowing About Coil Connectors — Volvo V40 Spark Plugs