Before you buy a used Renault Mégane (III).

Look out for: [EDC dual-clutch] EDC gearbox clutch slip (up to 19/12/2013); [EDC dual-clutch] "Check EDC" message (up to June 2016); [EDC dual-clutch] Loss of drive with the EDC gearbox (up to 30/10/2014); [EDC dual-clutch] Loss of drive and EDC gearbox light on; [5-speed manual] Gears will not engage (5-speed manual); [manual gearbox] Hard gear changes (up to 29/08/2013)

Ask them to check: Compare your symptom and your car's build date with this list. If they match, tell the workshop and ask them to check that part first before replacing others. The brand or a warranty extension covers some repairs: ask the dealer with the car's details.

Look out for: [suspension] Rear axle noise; [tyres] Tyre pressure light on (from January 2008 to March 2010)

Ask them to check: Compare your symptom and your car's build date with this list. If they match, tell the workshop and ask them to check that part first before replacing others. The brand or a warranty extension covers some repairs: ask the dealer with the car's details.

Look out for: [climate control] Left/right temperature difference (up to 01/04/2012); [climate control] Air conditioning fault; [electronics] Airbag light on (up to 23/02/2009); [ventilation] Ventilation faults (up to 19/03/2010); [ventilation] Ventilation jams (up to 14/04/2015); [doors and openings] Windows jam or drop (up to 16/09/2011); [multimedia] R-Link system bugs; [multimedia] Bluetooth fault (up to 09/06/2015); [sealing] Water leak at the front seats (until the end of production)

Ask them to check: Compare your symptom and your car's build date with this list. If they match, tell the workshop and ask them to check that part first before replacing others. The brand or a warranty extension covers some repairs: ask the dealer with the car's details.

Look out for: Oil leak (up to 26/01/2015); Loss of power (up to 26/06/2015); Oil leak (up to 01/01/2016); Excessive oil consumption and noise (up to 11/05/2016)

Ask them to check: Compare your symptom and your car's build date with this list. If they match, tell the workshop and ask them to check that part first before replacing others. The brand or a warranty extension covers some repairs: ask the dealer with the car's details.

Look out for: Oil needs topping up often; the level can reach the minimum with no warning on the dashboard. In advanced cases, timing noise, loss of power or serious engine damage.

Ask them to check: Measure oil consumption with the dipstick over several thousand km, ask the dealer for a diagnosis and the calibration update, and keep every maintenance invoice to request support.

Look out for: [2.0 16V/1.5 dCi] Vibration at idle (from 01/05/2009 to 08/02/2010); Hard starting on the dCi 105, with a risk of engine failure (from September 2009 to June 2010); Timing failure; Knocking when cold (up to the end of 2010); Engine stalls (up to 24/08/2011); Injection light on (up to 12/06/2012, K9K636 engine); Hard cold starting (up to 28/05/2013); Oil leak (up to 17/07/2013); Oil leak, pressure light on, noise or even engine failure (until the end of production); [1.5 dCi/1.6 dCi] Loss of power (up to 22/07/2015); [1.5 dCi/1.6 dCi/2.0 dCi] Will not start (up to 11/06/2015)

Ask them to check: Compare your symptom and your car's build date with this list. If they match, tell the workshop and ask them to check that part first before replacing others. The brand or a warranty extension covers some repairs: ask the dealer with the car's details.

Look out for: Engine noise and will not start (up to 01/07/2012); Fuel leak (from 24/11/2014 to 29/05/2015 or from 17/08/2015 to 11/12/2015); "Check injection" message; [1.5 dCi/1.6 dCi] Loss of power (up to 22/07/2015); [1.5 dCi/1.6 dCi/2.0 dCi] Will not start (up to 11/06/2015)

Ask them to check: Compare your symptom and your car's build date with this list. If they match, tell the workshop and ask them to check that part first before replacing others. The brand or a warranty extension covers some repairs: ask the dealer with the car's details.

Look out for: Will not start (up to 11/06/2015)

Ask them to check: Compare your symptom and your car's build date with this list. If they match, tell the workshop and ask them to check that part first before replacing others. The brand or a warranty extension covers some repairs: ask the dealer with the car's details.

Look out for: Metallic chain rattle, especially when cold or at idle; engine light with a crankshaft–camshaft correlation code; in serious cases the chain jumps and damages the valves.

Ask them to check: With any chain noise or a P0016 code, diagnose straight away: measure the stretch and check the tensioner and guides before the timing jumps. Shorten oil-change intervals.

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: Particulate-filter or emissions warning, limp mode with loss of power and frequent regenerations.

Ask them to check: Read the soot load with a diagnostic tool, run a forced regeneration at the garage and check the differential-pressure sensors and EGR. Make long road trips now and then.

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: Chain noise at high mileage; loss of power and emissions warnings in town use; injectors that will not come out when removed.

Ask them to check: Listen to the chain from cold, check injection and emissions codes, and before removing injectors have extraction tools ready. Keep oil changes up to date.

Look out for: Camshaft phaser on the 1.6 (K4M), stretched chain on the 1.4 TCe (H4J) and 1.2 TCe with a risk of serious failure, oil consumption, 1.9 dCi turbo, clogged EGR, juddering clutch; at the roadworthiness test, springs, shock absorbers, joints, lights and brakes.

Ask them to check: Listen to the chain when cold (TCe), measure oil consumption, clean the EGR; check the campaigns by VIN.

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.