Citroen C5 Aircross Engine Mount: Specs, Fitment & Common Faults

On the C5 Aircross, two genuinely free tests confirm a worn mount: watch the engine surge when switching off the ignition, plus a specific gear-change clunk pattern.

Illustration for editorial purposes

OEM Part Numbers

Accuracy note: we weren't able to verify a confident Citroen C5 Aircross engine mount part number at the time of writing. Please confirm the correct part via a Citroen dealer or parts specialist using your VIN.

Two Genuinely Useful, Free Tests to Confirm a Worn Mount

A genuinely simple, visual test worth trying before assuming anything else: switch off the ignition and watch the engine bay closely — on a car with a worn lower or rear engine mount, you can often physically see the engine surge or lurch forward as it comes to rest, rather than settling smoothly. This visual confirmation, combined with a distinctive clunk specifically when pulling away in first gear and changing into second, is a genuinely reliable pattern pointing toward this specific mount rather than other suspension or drivetrain components.

A genuinely useful distinguishing detail: a worn lower/rear mount typically produces the clunk specifically during the transition of pulling away and changing gear, or under acceleration and deceleration while in gear — but stays quiet if you simply rev the engine while sitting in neutral. If your clunk only appears during that specific gear-change moment and not while revving stationary in neutral, this pattern points toward the mount specifically rather than a more generic engine or suspension noise.

Genuinely good news on cost: this specific mount has been quoted at around £30 for the part alone, and is a straightforward job — with the car correctly jacked and supported on axle stands, replacement typically takes around ten minutes once you can access the two mounting bolts underneath the car.

The Part That Quietly Absorbs Everything

Engine mounts do a genuinely thankless job — holding a violently vibrating engine in place while isolating that vibration from the cabin — and when they wear out, the change is often gradual enough that owners adjust to it without realising something's actually wrong.

Before you buy: engine mount design and quantity vary by engine size and transmission type. Always confirm against your VIN before ordering.

What It Does

Engine mounts secure the engine and transmission to the chassis while absorbing vibration and movement, preventing that vibration from transferring directly into the cabin. Most versions of the C5 Aircross use several mounts working together — typically at least one on each side of the engine plus a torque mount — and a single failed mount can throw off the whole assembly's balance.

Fitment & Compatibility

Mount design and positioning differ between engine sizes and transmission types (manual versus automatic) of the C5 Aircross. Always confirm the exact mounts fitted to your specific engine and transmission combination before ordering, since manual and automatic versions often use different mount designs even on the same engine. Whether you're sourcing a replacement engine mount for your Citroen C5 Aircross from a dealer, specialist, or online marketplace, always check compatibility against your registration or VIN before buying, and confirm you're ordering the correct side — driver's side (RH in the UK) or passenger side (LH in the UK) — since these are not interchangeable.

Common Faults

Symptoms of Failure

Noticeable vibration through the cabin, especially at idle — often the earliest and clearest sign of a worn mount.
Clunking noise when accelerating or braking — points to a mount no longer properly restraining engine movement.
Visible engine movement when revving in neutral — a worn or broken mount can allow far more movement than normal.
Increased noise, especially over bumps — a failing mount can let the engine knock against surrounding components.

DIY Replacement Difficulty

This is a moderate-to-difficult DIY job depending on which mount needs replacing — some are easily accessible, while others require supporting the engine's weight with a jack or hoist while the mount is removed and replaced. Getting this step wrong risks damage to the engine or surrounding components. Expect 1–3 hours depending on which mount and how accessible it is on your specific engine layout.

OEM vs. Aftermarket

Reputable aftermarket engine mounts are generally a safe, cost-effective alternative to OEM parts, provided they match your exact engine and transmission specification. This is one area where cheap, poorly designed mounts can genuinely accelerate wear on adjacent components, so it's worth choosing an established brand over the very cheapest option available.

More Citroen Engine Mount Guides

The same part, covered across other Citroen models.