Before you buy a used Dacia Sandero (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: On the 1.2, coils and coolant loss from the thermostat housing; door locks, rust at the filler neck, an early-wearing clutch, ignition switch, starter and battery; at the roadworthiness test, suspension, steering, drive shafts, lights, brakes and exhaust mounts.

Ask them to check: Check both campaigns by VIN; watch the coolant; check the front axle, brakes and exhaust.

Look out for: Rust on the outer shell of the LPG tank. According to L'argus it does not affect safety, but it can make the car fail its roadworthiness test.

Ask them to check: Have the LPG tank looked at in the garage or at the roadworthiness test. If the shell is rusty, ask Dacia to replace the tank: owners are not told by letter, you have to ask yourself.

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.