Citroën C5

The DW12 uses two turbos in a parallel sequential arrangement. The small turbo works alone up to 1,400 rpm; both operate from 2,500 rpm. Seizure or bearing wear in one turbo causes uncontrolled boost pressure. Complex and expensive to repair.

Symptoms: Power loss, whistling/rattling noises, smoke, fault code.

The 2.2 HDi with EOLYS-based FAP is considered particularly susceptible to DPF problems. Lack of motorway driving leads to blockage. Regeneration failure increases oil dilution. Some mechanics fundamentally advise against this engine for short-trip drivers.

Symptoms: FAP warning light, power loss, limp mode, strong fuel smell in oil.

Under high mileage and thermal stress, DW12 cylinder heads can develop cracks. Known among mechanics as a problematic engine. In isolated cases, a complete engine swap from 2.2 to 2.0 HDi has been performed.

Symptoms: Coolant loss, mayonnaise in oil, overheating, white exhaust smoke.

The turbocharger on the DW12 2.2 HDi suffers from oil sludge and contamination that restricts the turbo's oil supply. Shaft play, whistling noises, and eventually bearing seizure are the result. Oil must be changed regularly.

Symptoms: Whistling turbo noise, blue smoke on acceleration, increased oil consumption above 0.5 L/1000 km, power loss. Turbo no longer spins up freely under load.

The crankshaft torsional damper wears at higher mileages. The inner and outer rings begin to slip, leading to rough running, knocking noises, and accessory belt drive problems. Known with heavy use.

Symptoms: Knocking/squealing at idle, belt noise, slightly rough engine running.

The EGR cooler on the DW12 2.2 HDi develops cracks and drips coolant onto hot exhaust parts where it evaporates. No visible external coolant loss. Risk of gradual overheating; coolant must be topped up regularly.

Symptoms: Gradual coolant loss with no visible external leaks, whitish steam from exhaust, cooling system requires frequent topping up, coolant warning light.

The Hydractive 3 suspension on the C5 I is a known money pit at higher mileages. Spheres lose their nitrogen charge and the ride becomes hard and uncomfortable. Leaking cylinders or a failed hydraulic block leads to complete failure and expensive replacement.

The BSI central control unit in the C5 I is notorious for complete failures in which fault messages for the immobiliser, gearbox, brakes, ABS and ESP appear simultaneously. Moisture in the ECU or corrosion at earth points are the most common causes.

Tie rods and tie rod ends on the C5 I have below-average durability. MOT reports document elevated tie rod wear as one of the most common defects on this model. Driveshafts and joints also show premature wear.

Vehicles from the early production years (2001–2004) show corrosion problems on the underfloor and front subframe. Brake lines and subframe welds rot through, especially in areas where road salt is used.