Peugeot 308 2.0 BlueHDi T9

The BlueHDi emissions system injects AdBlue into the SCR catalyst to reduce NOx. The injector can crystallise and block, while the pump (integrated into the sealed AdBlue tank) fails when fluid contaminates its circuit board. NOx sensors are also a common failure point, triggering fault codes P2200, U029D, P20E8, or P20EE. A NOx sensor replacement costs around €500-700 at a dealer. If the entire AdBlue tank and pump need replacing, costs reach €1,500-2,200. The issue typically appears after 80,000-120,000 km, particularly if the car sits unused for extended periods or if low-quality AdBlue is used. Pre-2018 models are more commonly affected. Using only branded AdBlue and keeping the system active with regular driving reduces the risk.

The 2.0 BlueHDi uses an additive-assisted DPF (Eolys/cerine system) that lowers the regeneration temperature. Despite this, short trips under 15-20 minutes prevent the DPF from reaching regeneration temperature. Symptoms include the engine warning light, anti-pollution fault message, and reduced power. A professional DPF clean costs €300-500. Full DPF replacement costs €800-1,500 including fitting. The Eolys additive tank also needs topping up approximately every 120,000 km (around €150 at a dealer). The 2.0 engine generates more exhaust heat than the 1.6, which helps with passive regeneration, but short-trip driving still causes problems. Using the correct low-SAPS oil (PSA B71 2312) is essential.

The EGR valve on the DW10 engine accumulates carbon deposits over time, especially with gentle driving and short trips. Symptoms include rough idling, loss of power, anti-pollution warnings, and increased fuel consumption. Cleaning the EGR valve costs around €150-250 at an independent garage. If the valve is beyond cleaning, replacement costs €350-900 depending on parts used. The 2.0 DW10 EGR is positioned in a way that makes removal relatively labour-intensive compared to smaller engines, which adds to the repair cost. Regular motorway driving and occasional spirited acceleration help keep the valve cleaner.

If the 308 is equipped with the EAT6 automatic (Aisin TF-80SC), the valve body solenoids can become contaminated, causing harsh or jerky shifts especially between 1st and 2nd gear. The problem typically emerges after the transmission reaches operating temperature and worsens over time. Peugeot originally classified the gearbox oil as a lifetime fill, which many specialists dispute. A valve body overhaul costs €600-900 at a specialist. Full gearbox rebuild can reach €1,500. A software re-adaptation procedure sometimes resolves milder cases. Prevention: change the ATF every 60,000 km despite the manufacturer recommendation. Manual gearbox versions are not affected by this issue.

The dual mass flywheel on the 2.0 BlueHDi can develop excessive play, causing juddering when moving off in first gear. The 2.0 engine produces more torque than the 1.6, which can accelerate DMF wear if the driver frequently loads the clutch at low RPM. A complete clutch and DMF replacement including slave cylinder and release bearing costs €1,000-1,800 depending on whether done at a dealer (around €1,600) or independent specialist (around €1,000-1,200). Labour time is approximately 7 hours. Solid flywheel conversion kits are available as an alternative.

The T9 308 has a known issue with premature front shock absorber failure, sometimes accompanied by spring breakage. Peugeot released updated parts to address the design weakness. Symptoms include knocking noises over bumps and uneven tyre wear. The 2.0 BlueHDi is slightly heavier than the 1.6, which may accelerate wear on the front axle components. A pair of replacement shock absorbers costs €200-400 for parts, plus €200-400 for labour. If springs also need replacing, add approximately €150-200. The issue typically appears between 60,000-100,000 km.

The heat exchanger (evaporator) located deep behind the dashboard can develop leaks due to internal corrosion from moisture and chemical deposits. The fault usually appears after 4-6 years of operation. Symptoms include gradual loss of AC performance and eventually no cold air. Repair requires complete dashboard disassembly, making it labour-intensive. The evaporator part itself costs €150-300, but labour can reach €500-800 due to the dashboard removal. The 308 T9 uses R1234yf refrigerant, which is also more expensive to recharge than the older R134a.