The 2021 Peugeot 5008 is a competent European crossover, but the PureTech 1.2L three-cylinder turbo engines have a well-documented weak spot with timing belt-in-oil failures that can grenade the motor, while the BlueHDi diesels suffer DPF clogging and EGR issues typical of modern emissions-strangled mills. The 8-speed automatic transmissions are generally solid but can develop mount failures and cooler leaks.
1.2L PureTech Timing Belt Wet-Belt Failure
Common · high severityTypical onset: 40,000-80,000 mi
Symptoms: Rattling or whirring noise on cold start, Check engine light with cam/crank correlation codes, Metal debris in oil on drain, Sudden catastrophic engine failure if belt disintegrates
Fix: The wet timing belt disintegrates in oil, sending debris through the engine. If caught early (noise stage), belt replacement with full oil system flush is 8-10 hours. If belt fails completely, you're looking at engine rebuild or replacement (25-35 hours). PSA issued extended warranty in some markets but not universally honored. This is the big killer on PureTech engines.
Estimated cost: $1,800-3,500 preventive belt job, $8,000-12,000 engine rebuild/replacement
BlueHDi DPF Clogging and Forced Regeneration Cycles
Common · medium severityTypical onset: 50,000-90,000 mi
Symptoms: Repeated DPF warning light, Limp mode during regen attempts, Loss of power under acceleration, Fuel dilution in oil from failed regens
Fix: Short trips and city driving kill these DPFs. Forced regen cycles with diagnostic tool take 1-2 hours but often band-aid the problem. DPF removal and cleaning (off-car) is 4-6 hours; replacement is same labor plus $1,500-2,000 for the part. EGR valve often needs cleaning or replacement simultaneously (add 2-3 hours).
Estimated cost: $400-800 regen/cleaning, $2,500-4,000 DPF replacement with EGR service
Transmission Mount Collapse (EAT8 Automatic)
Occasional · medium severityTypical onset: 60,000-100,000 mi
Symptoms: Clunk or thud when shifting from Park to Drive, Vibration at idle in gear, Excessive driveline movement visible when rocking car, Rough engagement during hard acceleration
Fix: The rubber transmission mounts deteriorate faster than expected, especially on the turbocharged models. Replacement is straightforward but requires transmission support — 2-3 hours per mount. Usually the front mount fails first, but inspect all three while you're in there. OEM mounts are pricey but aftermarket fails prematurely.
Estimated cost: $400-700 per mount with labor
Transmission Oil Cooler Line Leaks (EAT8)
Occasional · medium severityTypical onset: 70,000-110,000 mi
Symptoms: Transmission fluid spots under vehicle, Low fluid level on dipstick check (if equipped), Harsh or delayed shifts when hot, Burnt transmission fluid smell
Fix: The hard lines to the external cooler corrode at the crimped fittings or develop pinhole leaks where they run along the subframe. Replacing lines is 3-4 hours including fluid refill and proper bedding procedure. If ignored, low fluid causes clutch pack wear (then you're rebuilding the trans for $4,000+). Always inspect cooler itself for leaks while lines are off.
Estimated cost: $600-1,200 lines and fluid, $4,000-6,000 if transmission damage occurs
Cylinder Head Gasket Failure (1.2L PureTech)
Occasional · high severityTypical onset: 60,000-100,000 mi
Symptoms: White smoke from exhaust on cold start, Coolant loss with no visible leaks, Overheating under load, Milky oil on dipstick or cap
Fix: The three-cylinder PureTech runs hot and the head gasket can fail, often after the timing belt has contaminated the cooling system. Head removal is 12-16 hours; head resurfacing adds $300-500 at machine shop. Always test for combustion gases in coolant before buying. If head is warped beyond spec, you're replacing it ($1,200-1,800 part).
Estimated cost: $2,500-4,000 gasket job, $4,500-6,500 if head replacement needed
Rear Main Seal and Oil Pan Gasket Leaks (All Engines)
Occasional · low severityTypical onset: 80,000-120,000 mi
Symptoms: Oil spots under engine after sitting overnight, Oil accumulation on transmission bellhousing, Low oil level between changes, Oil smell in cabin when parked on incline
Fix: Both seals are prone to weeping on higher-mileage examples. Rear main requires transmission removal (8-10 hours on FWD models). Oil pan gasket is easier at 3-4 hours but subframe may need dropping for access. Often done together if trans is already out. Not urgent but address before it becomes a drip-per-day situation.
Estimated cost: $800-1,400 oil pan alone, $1,500-2,200 rear main with transmission out
Hard pass on the 1.2L PureTech unless timing belt has been replaced with updated parts and you have service records; the 1.5L BlueHDi is the safer bet if you drive highway miles, but expect typical diesel headaches — not a worry-free ownership experience either way.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.