Before you buy a used Dacia Logan MCV (I).

Look out for: Injection warning, jerking, rough idle, loss of power, smoke and sometimes a no-start.

Ask them to check: Read the codes (e.g. P0087, low rail pressure) and look for filings in the diesel filter. If the circuit is contaminated, replace pump, rail and injectors and clean the tank and lines.

Look out for: Noise or squeal around the belts; if the timing belt breaks, the engine stops suddenly and can be badly damaged.

Ask them to check: Keep to the timing-belt interval and always replace the full kit (belt, rollers and pulleys); check the auxiliary belt and its pulley.

Look out for: Uneven idle, jerks when accelerating, lack of power or the engine going into limp mode, sometimes with the engine warning light on.

Ask them to check: At the workshop: read the codes with diagnostic equipment (EOBD P0400 to P0404 or P0172; Renault DF077, DF084 or DF241), test the valve electrically and its opening with the engine warm, and find where the oil comes from (breather, turbo, level). Pierburg advises against cleaning it, as it can be damaged: it is replaced if faulty, and an engine ECU update sometimes solves it.

Look out for: Joints and track-rod ends that wear quickly, a short-lived exhaust, brake hoses from the sixth year and then discs, lights; batteries, starters, fuel pumps, door locks, crankshaft sensors and ignition leads.

Ask them to check: Check the campaigns by VIN; check the front axle, brake hoses, exhaust and lights before the roadworthiness test.

Look out for: The accessory belt slips, wears early together with its roller or breaks; if it breaks, power steering and alternator charging are lost.

Ask them to check: Check the accessory belt and the tensioner roller and whether the alternator has a fixed pulley. If the belt slips or is cracked, replace it with the roller; ask Dacia by VIN whether the car was in the 2015 action. If the belt breaks while driving, stop: without it the battery is not charged.

Look out for: Hard to start or will not start, stalls, loses power or jerks; sometimes air bubbles show in the clear fuel pipe.

Ask them to check: At the workshop, in this order: look for air and leaks in the low-pressure circuit and prime it; check the fuel filter bowl for metal swarf (if there is any, the whole injection system is replaced); measure the rail pressure, the IMV regulator's resistance (4.8–5.8 Ω) and each injector's return flow (25 ml at most in the test). A new injector's code must be written into the ECU.