Peugeot 307 1.6 HDi

The DV6 engine's turbocharger is highly sensitive to oil quality and service intervals. Carbon from leaking injector seals contaminates the oil, which then blocks the fine gauze filter in the turbo oil feed banjo bolt. Once oil supply is restricted, the turbo bearings overheat and fail within seconds at high RPM. The oil feed pipe itself is also prone to failure at the crimped junction where the hard pipe meets the banjo. Turbo replacement with a reconditioned unit, new oil feed pipe, strainer and banjo bolts costs approximately €800-1,000 at an independent specialist, or €1,200-1,500 at a Peugeot dealer. Preventive replacement of the oil feed pipe and regular 10,000 km oil changes with low-ash C3-spec oil significantly reduce this risk. Motor factors have reportedly stopped stocking exchange turbos for this engine due to high failure rates.

This is one of the most common failures on the DV6 engine. The copper sealing washer on each injector degrades over time, allowing hot exhaust gases to escape past the seal. This creates a thick, coal-like carbon deposit around the injector known as 'black death.' Injector number 3 is most commonly affected. If caught early, replacing the copper washer and cleaning costs around €150-300. If ignored, the carbon erodes a deep groove into the cylinder head injector seat, which can require cylinder head machining (€500-800) or even complete head replacement (€1,500-3,000). Symptoms include a diesel smell around the engine, rough idle on cold starts, and visible carbon buildup around the injector area. Regular inspection every 30,000 km is recommended.

The 307 was among the first Peugeot models to have DPF (FAP) fitted across the diesel range. The system relies on a cerine-based additive (Eolys) stored in a separate tank to lower the regeneration temperature. Short urban trips prevent proper regeneration, causing soot accumulation. Additionally, the fuel filler cap sensor that triggers regeneration cycles can fail, either preventing regeneration entirely or causing constant unwanted regenerations. DPF cleaning costs around €300-500, while full replacement runs €800-1,200 including fitting. The Eolys additive tank needs refilling approximately every 120,000 km at a cost of around €80-100. Cars driven regularly at motorway speeds rarely have DPF issues.

The BSI controls central locking, lights, immobilizer, and numerous other electrical functions. It is located in a position susceptible to water ingress from windscreen seals or heater matrix leaks. When water reaches the circuit board, it causes corrosion and intermittent or permanent failures. Symptoms include central locking malfunctions, random warning lights, indicators not working, and complete electrical shutdowns that resolve themselves. A BSI reset (battery disconnect for 15 seconds) can sometimes resolve minor glitches. Professional BSI repair costs approximately €150-250, while replacement with programming runs €400-800. Pre-facelift (2001-2005) models are more susceptible. The facelifted models from 2005 onward had a complete electrical system overhaul and are notably more reliable in this area.

The EGR valve on the 1.6 HDi accumulates carbon deposits over time, eventually sticking open or closed. When it fails, the anti-pollution warning appears on the dashboard, often accompanied by reduced engine performance. The valve is difficult to access on the 1.6 HDi compared to the 2.0 HDi variant. Aftermarket EGR valves are available for around €40-80, while OEM Valeo units cost approximately €200-300. Including labor (1-2 hours), total replacement costs €250-500. Cleaning can sometimes restore function temporarily but replacement is usually more reliable long-term. Regular spirited driving on motorways helps keep the valve cleaner.

The diesel models use a dual mass flywheel to absorb engine vibrations. Over time (typically 120,000-180,000 km), the internal springs weaken, causing noticeable judder when pulling away from rest and a metallic rattle at idle with the clutch pedal released. When replacing the DMF, it makes sense to replace the clutch kit simultaneously as the gearbox must be removed regardless. A complete clutch kit with DMF replacement costs approximately €600-800 at an independent garage, or €900-1,200 at a dealer. Solid flywheel conversion kits are available for around €250-350 as an alternative, though they transmit more vibration to the cabin.

The COM2000 module integrates the indicator stalk, wiper controls, and lighting controls into one unit. Internal contacts wear over time, causing intermittent or complete failure of indicators, wipers, or lights. A clicking noise from the steering column area is an early warning sign. The genuine Peugeot replacement part costs approximately €300-450, while reconditioned units are available for €100-150. Aftermarket alternatives exist from around €50. Labor is straightforward (about 1 hour) but care is needed not to damage the airbag clock spring. Including fitting, expect €200-500 depending on parts choice.

The 307's front suspension is a well-known weak point. Anti-roll bar drop links typically need replacing every 40,000-60,000 km (parts cost €15-30 per pair). Control arm silent blocks wear noticeably by 80,000-100,000 km, causing vague steering and clunking over bumps (€150-300 for replacement including labor). Wheel bearings also fail earlier than on many competitors, typically showing as a humming noise that increases with speed. The SW estate versions experience even faster shock absorber wear due to the additional weight. Individual repairs are cheap, but the frequency means suspension work is an ongoing ownership cost.