Peugeot 307

The plastic impeller of the water pump can disintegrate from as early as 50,000 km. Fragments enter the timing belt drive and cause the belt to snap with subsequent total engine destruction.

Symptoms: Coolant temperature rises unusually, coolant loss without visible leak, faint grinding or squealing from the timing belt drive, sudden engine shutdown when belt snaps

The dual-mass flywheel wears prematurely, especially on the 107 hp variant. Oil dilution from DPF regeneration accelerates wear. The clutch should always be renewed at the same time.

Symptoms: Squealing or clattering when starting and stopping the engine, pronounced vibrations at idle, juddering when pulling away, knocking at low revs under load

Leaking injectors allow diesel into the engine oil, drastically reducing its lubricity. The rising oil level is often overlooked. This can cause piston and bearing damage.

Symptoms: Diesel smell at the dipstick, oil level rises above maximum, strong exhaust smell inside the car, engine judders or knocks more than usual, increased fuel consumption

After switching off a hot engine the oil lines to the turbocharger can coke up. On the next start the turbocharger briefly runs without lubrication. Mainly affects the more powerful DW10 variants.

Symptoms: Increasing whistling or whining from the turbocharger, oil spots under the car in the turbo area, gradual power loss, blue smoke after the engine has been standing

Internal EGR cooler failure routes coolant into the exhaust gases. Coolant disappears without visible external leak. Repair requires 13.2 hours of labour. Cost 800–2,000 €.

Symptoms: Coolant drops without visible leak, white smoke from exhaust, heater won't warm up

The PSA-proprietary additive (Eolys) is mixed into the fuel and enables regeneration at a lower temperature. A defective additive pump or empty reservoir prevents regeneration and clogs the FAP prematurely. Change interval 120,000–180,000 km.

Symptoms: Warning 'particulate filter will soon clog', increased fuel consumption, power loss, regeneration attempts visible as idle speed fluctuations

The multi-function BSI unit (Boîtier de Servitude Intelligent) is extremely prone to faults. Splash water can disable the engine management. Instrument cluster, window regulator and central locking failures often trace back to the BSI.

Wishbones, anti-roll bar drop links and rear axle bearings on the 307 wear above-average quickly. TÜV/MOT inspectors regularly flag the high suspension wear. Axle and steering joints wear heavily and are a common reason for MOT failures.

ADAC and TÜV rate brake disc wear as very high. The braking system is flagged at inspection above-average frequently. Both front and rear brake discs are affected.

Steering joints and track rod ends on the 307 wear significantly faster than average. TÜV/MOT inspectors regularly flag the steering. Worn-out track rod ends lead to imprecise steering and are safety-critical.