2016 Peugeot 508 SW diesel with an oil-covered engine and a particle filter at the end of its life

This 2016 Peugeot 508 SW GT-Line 1.6 BlueHDi had a lot going for it: original paint on every panel, an excellent chassis, four brand new tyres and a good drive. It still failed our inspection. The whole engine was coated in oil from a source nobody could yet identify, the particle filter had reached the end of its life, and the work needed added up to roughly what the car was worth.

The car

The 508 SW is the estate version. This one has the 1.6 BlueHDi 120 diesel, engine code BHZ, with a 6-speed manual gearbox and front-wheel drive. It was first registered new in Ireland in April 2016 and had four owners. The odometer read 248,081 km, the same on the dashboard, the engine computer and the national register, and the mileage history was credible. There was no service book and no invoices. The history checks were clear: no finance, no write-off, no damage recorded, and the NCT was valid to April 2028.

What we found

An engine covered in oil

The entire engine was coated in oil, around the upper engine, the turbocharger area and the sump, and so was the outside of the gearbox. Our crankcase pressure test showed positive pressure, which on this engine points first at the crankcase breather and PCV valve, a cheap part. But fuel and oil mix on top of the engine also raised the possibility of a leaking injector seal. Until the engine is steam cleaned and run again, nobody can say whether the repair costs a few hundred euro or several thousand.

A particle filter at the end of its life

The engine computer stored code P242F, particulate filter worn, and it came straight back after clearing. Its own figures agreed: 0 km of life remaining, 59% loaded with ash that regeneration cannot burn off, and the original filter fitted 248,080 km earlier. The car drove normally because the filter was not blocked, but the gap between regenerations had shortened from an average of 339 km to 188 km.

No timing belt record

This engine drives its camshafts with a rubber timing belt. The interval we work to is 165,000 km or 10 years, and with no record of a change this belt was overdue on both. If it fails, the engine is normally beyond economic repair.

Other faults

• Fuel correction faults stored for cylinders 3 and 4, both returning after clearing. The injectors need a bench test.
• Two AdBlue system faults that also returned after clearing and need a dedicated test.
• Rear brake discs 90% worn, with corrosion breaking away the outer edges.
• A rear wheel bearing audible while driving, and a clutch that worked but felt worn.
• The passenger airbag was switched off at the glovebox key switch, and a front right side airbag line fault had been stored once.

Of 37 codes on the first scan, 35 cleared and did not return. Their pattern, with a battery charge status of 14%, pointed to a low voltage event rather than failed parts.

What it would cost

The report puts the work identified at €3,910 to €7,670: the leak diagnosis, the breather and camshaft cover gasket, the timing belt and water pump, the particle filter clean or replacement, the injector test and one injector, the AdBlue diagnosis, the clutch with its dual mass flywheel, the rear brakes, the wheel bearing and smaller items. That excludes whatever the leak diagnosis finds. Cartell valued the car at €4,750 to €6,250 retail.

Our verdict

Fail, do not purchase in current condition. No single catastrophic defect drove it. The biggest fault could not be scoped before purchase, so it could not be written as a condition, and the work needed equalled or exceeded the car's value. The strengths were genuine: no crash damage, an excellent chassis and suspension, a very good interior for the mileage, and a smooth drive with no smoke and no warning lights. Our inspector described it as a project rather than a purchase.

Buying a used 508 1.6 BlueHDi in Ireland: what to check

• Ask for proof of the timing belt and water pump change. Without it, treat the belt as never done.
• Have the particle filter data read: distance remaining and ash loading tell you more than whether the car regenerates.
• Look at the engine and gearbox for oil before you look at anything else, and ask for a crankcase pressure test if it is wet.
• AdBlue system faults and injector problems are known weak points on this model, so check the stored codes and the injector correction values.
• On a manual, a worn clutch usually means the dual mass flywheel too, which is not a small job.

A straight body and new tyres are easy to see, and a tired engine is easy to miss, which is why it is worth checking under the bonnet before you pay.