Citroën C5 – the common problems and what you need to know

The Citroën C5 is a comfortable mid-size car with a character of its own, but anyone considering buying one – or who already drives this French model – would be wise to look into the most common problems. From engine issues to the unique hydropneumatic suspension, the C5 calls for specific attention and regular maintenance. This helps you avoid costly surprises. Want to know exactly what you should look out for?

Why the Citroën C5 is still attractive

The Citroën C5 is known for its comfortable road manners and spacious interior. The French brand positioned this model as an affordable alternative to more expensive German mid-size cars. The characteristic suspension and smooth driving behaviour make the C5 popular. People who cover long distances in particular appreciate these qualities. That said, the model does have its weak points. Owners regularly report technical problems that are specific to this model. Car problems with Citroën are not unusual, and the C5 is no exception. Knowing about these vulnerabilities helps you make targeted choices when it comes to purchase and maintenance.

The most common problems with the C5

The Citroën C5 has problems in several areas. Engine faults occur on both diesel and petrol engines. The unique Hydractive suspension is susceptible to leaks and failing pumps. Electrical faults occur regularly. These are often caused by problems with the BSI module. The transmission can show defects, especially on automatic versions. In addition, there are complaints about the running gear, braking systems and smaller interior issues. The following sections cover each of these topics in detail.

Engine problems: diesel and petrol engines under the microscope

The C5’s diesel engines regularly suffer from problems with the EGR valve (exhaust gas recirculation). This component recirculates exhaust gases to reduce emissions. It mainly affects the 1.6 and 2.0 HDi variants. HDi stands for High-pressure Diesel injection, Citroën/PSA’s type of diesel engine. This valve becomes clogged. That can lead to loss of power and a poor idle speed. The turbo is also prone to wear, especially if the engine is not allowed to warm up properly before being used hard.

On petrol engines, timing chain issues occur. This is especially a problem with the 1.8 and 2.0-litre variants. The chain can stretch or lose tension. That results in rattling noises when starting. If not dealt with in time, this can lead to serious engine damage.

In addition, some diesel engines show problems with the injectors. Faulty injectors cause an uneven idle and black smoke from the exhaust. Replacement is expensive, particularly when several injectors need to be replaced at the same time. When buying or servicing, always check the history of the EGR valve, turbo and timing chain.

Hydractive III+ suspension: comfort at a price

The hydropneumatic suspension is a hallmark of Citroën. The C5 uses the Hydractive III+ system. This system automatically adjusts the suspension based on driving conditions. In this way, it delivers an exceptionally comfortable driving feel. However, the system is complex and prone to faults. Leaks in the hydraulic lines are common, especially on older models. This leads to soft suspension and a warning light on the dashboard.

The hydraulic pump can also fail. Symptoms include hard suspension, a loud droning noise and increased fuel consumption. Replacing the pump is expensive and requires specialist knowledge. The suspension spheres can also leak. This results in the car sagging on one side. Regular checks of the hydraulic system and topping up the hydraulic fluid in good time can prevent many problems. Have this maintenance carried out by a specialist who is familiar with Citroën systems.

Electrical faults: the C5’s gremlins

Electrical problems are a frequently heard complaint among C5 owners. The BSI module (Boîtier de Servitude Intelligent) is a well-known weak spot. This is the central electronic control unit that manages various systems in the car. Faults in the BSI can lead to the failure of multiple functions. The lights may stop working. The central locking may no longer operate. The windscreen wipers can also stop. Other electrical components may likewise show problems. In some cases the car refuses to start due to a defective BSI.

Sensors also regularly develop faults. The parking sensors can give false alerts, and the rain sensor sometimes does not respond properly. Problems with the airbag warning light occur, often caused by poor contacts under the seats. In addition, the electric windows can judder or fail completely. This is usually the result of a faulty switch or motor in the door. With electrical problems it is sensible first to check the battery and earth connections. That way you avoid replacing expensive components that are not actually defective.

Transmission problems: manual and automatic

The C5’s manual gearboxes are generally reliable. However, they can show wear on the clutch and flywheel. Vibrations when changing gear or a slipping clutch indicate that replacement is due. There are more problems with the automatic transmission. This mainly concerns the AL4 and EAT6. These are two types of automatic gearbox. Jerks when changing gear, delayed response and sometimes even complete failure are reported complaints.

The AL4 automatic is sensitive to contaminated transmission oil. Regular replacement of the oil and filter can extend the life of the automatic gearbox. With the EAT6, electronic faults are not unusual. These are often caused by a defective TCU module. This is the electronic control unit that manages the transmission. Replacing it is expensive. During a test drive, pay attention to smooth gear changes and check whether any warning lights for the transmission appear on the dashboard.

Chassis and brakes: safety first

Besides the specific problems with the Hydractive suspension, other parts of the chassis can also cause trouble. Wheel bearings wear and produce a droning noise that increases with speed. Suspension arm bushes can split. This leads to rattling noises and poor handling. The driveshafts can develop play. You can recognise this by a clicking noise when turning.

The C5’s braking system is generally reliable, but older models can show problems with the electronic parking brake. It can seize or refuse to release. This happens especially after periods of inactivity. Corrosion on the brake discs and sticking callipers are seen on cars that are rarely used. During servicing, always check the thickness of the brake discs and the condition of the brake fluid.

Interior and finish: minor irritations

Overall, the C5 has a solid interior, but there are complaints here too. Rattling interior parts are often reported. This mainly occurs around the dashboard and centre console. Plastic clips can break, causing loose panels. The finish of some buttons and switches is not always top quality and can wear.

Electric windows can judder or fail completely. The air conditioning systems can also develop faults, often due to a leaking condenser or a defective compressor. Fortunately, these problems are usually not critical, but they can reduce driving comfort. When buying, check that all electrical functions are working properly.

Recognising symptoms: watch out for these signs

Early recognition of problems can prevent expensive repairs. Watch out for the following warning signs:

• Rattling noises when starting indicate timing chain problems.
• Black smoke from the exhaust points to faulty injectors or EGR problems.
• Soft suspension or the car sagging on one side points to leaks in the hydraulic system.
• Warning lights on the dashboard should always be taken seriously.
• Jerks when changing gear may indicate transmission problems.
• Droning noises while driving often point to wheel bearings or driveshafts.

Do not take these symptoms lightly. Have the car checked by a specialist as soon as you notice any of these signs.

Preventive maintenance: how to extend its lifespan

Regular maintenance is even more important on the C5 than on many other models. Follow these tips:

• Replace the engine oil and filters according to the prescribed service schedule.
• Have the EGR valve cleaned regularly. This is especially important on diesel engines.
• Check the hydraulic system annually. Top up if necessary.
• On automatics, replace the transmission oil every 60,000 kilometres.
• Check the timing chain on petrol engines at around 100,000 kilometres.
• Have electrical faults diagnosed in good time. This prevents them from getting worse.

Look for a workshop with experience of Citroën models. The C5’s unique systems require specialist knowledge.

Repair costs: what to expect

Repair costs on the C5 can be quite high. This is especially true when it comes to the suspension or transmission. An overview of indicative prices:

• Cleaning the EGR valve: between 150 and 300 euros
• Replacing the turbo: between 800 and 1,500 euros
• Replacing the timing chain: between 600 and 1,200 euros
• Replacing the hydraulic pump: between 1,000 and 2,000 euros
• Repairing or replacing the BSI module: between 300 and 800 euros
• Overhauling the automatic transmission: between 1,500 and 3,000 euros

These prices are indicative and can vary by region and workshop. Always request several quotes and choose a reliable specialist.

Buying a used C5: checklist for buyers

Thinking about buying a used C5? Then use this checklist during the inspection:

• Check the service history. Look for evidence of regular maintenance.
• Test the suspension. Press down on each corner of the car and see whether it returns immediately.
• Watch for warning lights on the dashboard during a test drive.
• Check that all electrical functions work. Test windows, lights and central locking.
• Listen for unusual noises from the engine and transmission.
• Ask whether the EGR valve and timing chain have recently been replaced or inspected.
• Check for leaks under the car. Pay particular attention to the suspension and engine.
• Ask for a test drive of at least 30 minutes. This lets you properly test the automatic gearbox.

Consider a professional inspection before you go ahead with the purchase. The cost of this does not compare to the potential repair costs of hidden defects.

The C5: a car that needs attention

The Citroën C5 offers a comfortable driving experience and a character of its own. The model does, however, require specific attention. The well-known problems with the suspension, electronics and transmission can be costly if they are not tackled in time. Regular maintenance by a specialist and early recognition of symptoms are the keys to a reliable C5. For those prepared to invest this extra care, the C5 still offers an attractive alternative in the mid-size class. Weigh up the pros and cons carefully. If in doubt, always take a test drive and have a professional inspection carried out.