Citroën C5

The turbocharger on the 2.2 HDi UHZ wears sooner than in private-car use due to high mileage and commercial vehicle loading. Oil sludge from extended service intervals is a frequent cause. Flushing the turbo oil feed line at every oil change is recommended.

Symptoms: Whistling, power loss, blue exhaust smoke, oil in intake hose.

Copper seals and rubber seals on the 2.2 HDi injectors leak under high temperature swings and intensive load operation. Leaking injectors contaminate the oil and cause combustion gas blow-by.

Symptoms: Soot deposits around injectors, oil contamination in engine bay, rough idle.

Commercial operation with short trips is harmful to the DPF. The EOLYS-based FAP system only regenerates on sufficiently long journeys. In urban delivery use, regenerations frequently fail and the filter clogs prematurely.

Symptoms: FAP warning light, limp mode, strong fuel smell, increased fuel consumption.

The timing chain of the 3.0 HDi V6 (UHZ) stretches at higher mileages. In rare cases the camshaft sprocket spins on its taper, causing immediate engine failure. Timing tools are required for adjustment work.

Symptoms: Rattling from the timing area on cold start, rough idle, engine warning light with camshaft fault, in the worst case abrupt engine failure.

The 3.0 HDi V6 has two turbochargers that suffer bearing damage from oil sludge caused by infrequent oil changes or short-trip driving. When one turbo fails, power loss and high oil consumption result.

Symptoms: Whistling turbo noise, heavy blue smoke from exhaust, noticeable power loss especially in the upper rev range, increased oil consumption.

The vacuum actuator for the swirl flaps on the 3.0 HDi V6 has a rubber diaphragm that is cut and worn through by sharp plastic edges. The actuator then loses vacuum and the flaps are no longer controlled correctly.

Symptoms: Power loss at part load, reduced throttle response, swirl flap fault code, occasional limp mode under heavy load.

The optional Hydractive 3+ suspension (standard on Exclusive trim) in the C5 II starts leaking at spheres and cylinders from around 80,000 km. A 'Suspension defective' message appears and the car limits top speed to 90 km/h.

The electric power steering in the C5 II is connected to the BSI control unit. BSI faults or ECU problems cause the power assistance to fail. A frequently reported issue is sudden loss of assist while the engine is running.

The automatic gearbox in the C5 II (2008–2017) shows typical problems pulling away from standstill. Only after firm throttle input does the gearbox engage properly. A gearbox flush or software update often helps, but solenoids are due at higher mileages.

The 2016 MOT report documents above-average frequency of tie rod wear and increased driveshaft wear on the C5 II. Tyre inner edge wear and clunking in corners are typical symptoms.

According to MOT reports, the C5 II frequently shows oil leaks at engine and gearbox seals as well as occasional BSI control unit problems. Faulty EGR valves cause short-circuit risks at the starter cable connection (recall 2013–2017).