2020 PEUGEOT 308

Typical onset: 60,000-100,000 mi

Symptoms: Blue smoke on cold start or hard acceleration, Low oil warning between service intervals (1+ quart per 1,000 mi), Reduced power under boost, Turbo whine or grinding noise

Fix: The Prince/THP engine burns oil through worn piston rings or valve stem seals; turbo failure often follows if oil starvation occurs. Ring job requires engine-out, 18-24 hours labor. Turbo replacement alone runs 8-10 hours. Many opt for used engine swap at this point.

Estimated cost: $3,500-6,500

Typical onset: 70,000-110,000 mi

Symptoms: Transmission overheating warning on dash, Harsh or delayed shifts when warm, Limp mode activation in hot weather or towing, Pink or milky transmission fluid (coolant cross-contamination)

Fix: The integrated cooler in the radiator fails, mixing coolant and ATF which destroys the transmission. Requires radiator replacement (5 hours) plus full transmission fluid flush. If contamination went unnoticed, full rebuild or replacement needed (15-20 hours). Act immediately on overheating warnings.

Estimated cost: $1,200-2,800 (cooler only) / $4,500-7,000 (with rebuild)

Typical onset: 50,000-80,000 mi

Symptoms: Clunking on shifts or throttle transitions, Vibration through cabin at idle in gear, Excessive driveline movement visible during acceleration, Gear selector feels notchy or imprecise

Fix: The hydraulic transmission mount fails early on this platform, especially upper mount. Replacement is 2-3 hours with some subframe support required. OEM mounts mandatory—aftermarket versions fail within 10,000 mi.

Estimated cost: $400-750

Symptoms: One or both headlights intermittently cut out, DRL or low beam stuck on or off, Headlight error messages on dash, Flickering during engine start

Fix: LED driver boards in the headlight assemblies fail due to thermal cycling or moisture intrusion. No repair option—full assembly replacement required. 1.5-2 hours per side with bumper removal for access. Peugeot parts pricing is brutal here.

Estimated cost: $800-1,400 per side

Typical onset: 40,000-90,000 mi

Symptoms: Intermittent no-start conditions, Random electrical gremlins (wipers, HVAC, fuel pump), Multiple seemingly unrelated warning lights, Clicking from fuse box area, no crank

Fix: The underhood fuse box is poorly sealed and collects moisture, corroding terminals and killing relays. Diagnosis can take 2-4 hours chasing ghosts. Individual relay/fuse replacement sometimes works (1 hour), but often the entire BSI (body control module integrated in box) needs replacement and programming (4-6 hours).

Estimated cost: $300-800 (relays) / $1,500-2,500 (full BSI)

Typical onset: 45,000-75,000 mi

Symptoms: Pulling to one side during braking, One front wheel excessively hot after driving, Rapid pad wear on one side, Grinding or dragging sensation

Fix: Caliper slide pins corrode in the brackets despite regular service. Simple rebuild usually buys 20,000 mi; most shops recommend new loaded calipers. 1.5 hours per side including brake fluid flush. European calipers aren't cheap.

Estimated cost: $350-600 per axle