2020 PEUGEOT 508

Typical onset: 60,000-100,000 mi

Symptoms: Metallic rattling on cold start that disappears after a few seconds, Check engine light with timing correlation codes (P000A, P0016), Sudden loss of power or rough running if belt stretches significantly, Oil contamination with black rubber particles visible on dipstick

Fix: The 1.6L PureTech uses a wet timing belt running in engine oil — it deteriorates and sheds material. Full timing service includes belt, tensioners, water pump, and oil system flush. 6-8 hours labor. If belt fails completely, expect bent valves and potential piston damage requiring head removal and valve work, adding another 10-14 hours.

Estimated cost: $1,800-2,800 preventive / $4,500-7,000 if valves bent

Typical onset: 40,000-80,000 mi

Symptoms: Judder or hesitation during 2nd to 3rd gear upshifts, especially when warm, Delayed engagement when shifting from Park to Drive, Transmission fault warning with limp mode (rare but documented), Clunking from transmission mount area under acceleration

Fix: Aisin EAT8 8-speed auto generally reliable but can develop mechatronic valve body issues or torque converter shudder. Fluid change with official PSA ATF often resolves early symptoms (2 hours). Mechatronic replacement is 8-10 hours. Worn transmission mounts exacerbate feel of any shudder — mounts alone are 2-3 hours.

Estimated cost: $400-600 fluid service / $2,200-3,500 mechatronic / $350-550 mounts

Typical onset: 50,000-90,000 mi

Symptoms: Frequent DPF regeneration warnings, especially on short-trip driving, Loss of power and rough idle due to EGR valve carbon buildup, Check engine light with P2002 (DPF efficiency) or P0401 (EGR flow), Black smoke on hard acceleration if EGR stuck open

Fix: Modern diesels demand highway use for proper regen. EGR cleaning is 3-4 hours, DPF removal and professional cleaning or replacement 4-6 hours. Many shops recommend doing both simultaneously if one is clogged. Software updates can help regen strategy but won't fix mechanical clogging.

Estimated cost: $600-900 EGR clean / $1,200-2,000 DPF service / $2,500-3,200 new DPF

Typical onset: 70,000-110,000 mi

Symptoms: Hard starting, especially when cold, with extended cranking, Rough idle and misfires with white smoke from exhaust, Fuel in oil (dilution) due to failed injector seals, P0087 fuel rail pressure codes or multiple injector circuit codes

Fix: The 1.5L BlueHDi can suffer injector seal leaks allowing fuel into crankcase or combustion chamber wash-down. Single injector replacement is 3-4 hours; if fuel contaminated oil, expect oil change and potential bearing wear inspection. All four injectors plus fuel filter and system flush runs 8-10 hours if multiple are failing.

Estimated cost: $800-1,200 per injector / $3,000-4,500 all four with system service

Typical onset: 60,000-100,000 mi

Symptoms: Reduced electric-only range (below 15-20 miles when new was 30+), Hybrid system fault warning with vehicle defaulting to gasoline-only mode, Onboard charger failure preventing AC charging at home, High-voltage battery cooling fan running constantly

Fix: The 13 kWh battery pack can degrade noticeably by 80k miles, especially if fast-charged frequently or exposed to extreme heat. Battery health diagnosis is 1-2 hours; onboard charger replacement 4-5 hours. Full traction battery replacement is dealer-level work (6-8 hours) and extremely expensive. Most shops will replace charger or cooling components, not the pack itself.

Estimated cost: $1,500-2,200 onboard charger / $8,000-12,000+ battery pack (often dealer-only)

Symptoms: Touchscreen becomes unresponsive or freezes on startup, Backup camera image distorted or fails to display, Loss of Android Auto / Apple CarPlay connectivity, Instrument cluster (digital) goes blank or shows garbled graphics

Fix: PSA's NAC (New Audio Connect) system has firmware bugs. Many issues resolve with software updates (0.5-1 hour). Hardware failures in the head unit or display require module replacement — 2-3 hours labor. Digital instrument cluster issues sometimes trace to loose connectors behind the panel (1 hour diagnostic).

Estimated cost: $150-250 software update / $800-1,400 head unit / $1,200-1,800 digital cluster