Peugeot 308 GTi T9

The 270 by Peugeot Sport variant uses four-piston Alcon brake calipers with 380 mm discs. The chrome-plated pistons react with salt and moisture, causing corrosion that makes them seize in the bores. Symptoms include uneven pad wear, pulling under braking, and excessive disc wear on one side. This is a well-documented issue across 308 GTi 270 and RCZ R forums. The full OEM replacement cost is around 2,800 euros for new Alcon calipers. A full caliper rebuild with stainless steel piston kits (from specialists like Godspeed Brakes) costs approximately 1,500 euros including labor. The most cost-effective solution is to swap to the 250 model's standard brake setup for approximately 900 euros, though this reduces braking performance. OEM front discs alone cost 600-700 euros per pair. This issue does not affect the 250 variant, which uses standard single-piston calipers with 330 mm discs.

The HPFP remains a weak point on the EP6FDTR engine, though it has been revised with higher fuel pressure compared to the earlier EP6CDT. On the GTi's higher-output tune, the pump works closer to its capacity limits, which may shorten its lifespan. Symptoms include intermittent stuttering, difficulty starting, rough idle, and loss of power. Fault code P0087 (fuel rail pressure too low) is the typical diagnostic indicator. The pump typically fails between 60,000 and 120,000 km. A genuine replacement pump costs 500-650 euros; remanufactured units are available for 250-350 euros. Total repair cost including labor is 500-800 at an independent specialist or 900-1,200 at a Peugeot dealer. Peugeot has occasionally offered goodwill contributions on cars under 6 years old.

The 1.6 THP engine generates considerable heat in a compact engine bay, and the ignition coils take significant thermal stress. Water can also collect around the coil packs and cause corrosion. Many experienced 308 GTi owners recommend replacing all four coil packs and spark plugs every 30,000-40,000 km as preventive maintenance. When a coil fails, the engine misfires on the affected cylinder, causing juddering and power loss. A single coil costs 30-60 euros aftermarket or 60-90 euros genuine. Replacing all four coils with spark plugs costs 150-400 euros total including labor. While individual coil failure is not expensive, repeated failures without addressing the root cause (moisture ingress, heat management) can be frustrating.

As with all direct-injection engines, fuel does not wash over the intake valves, allowing carbon deposits from PCV oil vapors to accumulate. The THP engine's PCV routing design makes it particularly susceptible. Symptoms develop gradually: rough idle, reduced throttle response, and power loss of up to 15-20 percent. The issue typically becomes noticeable between 50,000 and 80,000 km. Walnut blasting is the standard cleaning method, costing 400-600 euros at a specialist. The buildup will recur every 40,000-60,000 km. Regular spirited driving at higher RPM helps slow the accumulation, while predominantly urban short-trip driving accelerates it significantly. Some owners view this as scheduled maintenance rather than a fault, but the cost is unpredictable since it depends on driving style.

The 308 GTi's firmer suspension setup accelerates front shock absorber and top mount wear. The rubber top mounts dry out and collapse, producing a knocking or clunking noise over bumps and speed bumps. Some owners have had shocks replaced under warranty as early as 20,000 km. Peugeot released updated dampers with revised rebound and compression values. On higher-mileage cars, expect to replace the front shock absorbers, top mounts, and possibly coil springs together. A pair of front shock absorbers with top mounts costs 400-600 euros at an independent garage. If coil springs have also broken (a known 308 platform issue), add 200-400 euros. The bottom coil of the spring is encased in a plastic tube, making breakage difficult to spot visually.

The turbo wastegate actuator can seize if the car is driven too gently for extended periods, as carbon deposits build up on the mechanism. Symptoms include erratic boost delivery, overboost fault codes, limp mode, and check engine light. If caught early, the actuator can be cleaned or replaced for 400-600 euros. However, if the turbo internals are damaged from operating with a stuck wastegate, a full turbo replacement is needed at 1,000-1,500 euros. Regular spirited driving helps prevent this issue. Some owners have found that a blocked atmospheric port filter on the boost control solenoid can mimic wastegate symptoms. Using premium fuel (98 octane) helps keep the turbo system cleaner.

The 270 by Peugeot Sport variant's Torsen limited-slip differential produces a distinctive moaning or groaning noise during tight turns, U-turns, and parking maneuvers. This is a known characteristic of Torsen-type differentials and is not a defect. The noise can be reduced by adding a friction modifier to the transmission oil, such as 75 ml of Penrite Limslip added to the standard Peugeot-spec 75W transmission oil. Some owners have switched to Motul Gear 300 LS 75W-90, which reportedly eliminates the noise and improves shift quality. There is a theoretical 10 percent reduction in torque bias ratio when using friction modifiers, but this is not noticeable on road use. Cost is essentially zero beyond the oil additive itself.

Early 308 T9 models (2014-2016) are known for AC compressor failures. The compressor seizes internally, requiring full replacement. A replacement compressor plus system flush and dryer replacement costs 600-1,000 euros depending on whether genuine or aftermarket parts are used. Some 2015-2016 cars had this covered under warranty, but all GTi models are now outside the 2-year factory warranty period. The issue typically manifests as warm air from the vents and a clicking or grinding noise from the compressor area. Cars that have already had the compressor replaced with the updated part are unlikely to have the issue again.