Renault EDC (DW5) — 7-speed wet dual-clutch transmission: known problems
16 sourced reports, with what to check before you buy. Each one links to the page it was reported on.
Costly or dangerous
Delayed engagement from standstill in dw5 7-speed DCT
Noticed on a test drive
The Renault 7-speed DCT (dw5) can hesitate before moving when you press the accelerator from a stop. This is caused by the dry clutch and transmission control module settings, and can make junctions awkward. It may worsen over time and lead to expensive clutch or gearbox repairs.
What to check. During the test drive, repeatedly stop and then accelerate gently from a standstill. Listen for any delay or jerkiness in engagement. Check for a transmission fluid service history, and consider a diagnostic scan for fault codes related to clutch or gearbox actuators.
The EDC gearbox's input shaft seal is a known weak point; oil leaks can damage the clutch. Replacement includes an updated seal, indicating the original is prone to failure.
What to check. Check under the car for gearbox oil leaks, especially around the bell housing. Ask if the clutch or input shaft seal has been replaced; a replacement with updated seal is a plus.
Owners have reported problems with the EDC automatic gearbox on this model, indicating a chronic transmission issue that could lead to expensive repairs. Buyers should be aware and test drive carefully.
What to check. During test drive, check for jerky or hesitant gear changes, unusual noises, clutch judder, and warning lights. Also verify if the gearbox fluid has been changed per schedule if applicable.
EDC dual-clutch judder and mechatronic failure (Mégane III/IV)
Noticed on a test drive
The dual-clutch automatic gearbox on this Mégane is known for clutch pack wear causing judder, and mechatronic unit failures that disrupt gear selection. These are expensive to repair and may not be caught by a standard inspection.
What to check. During a test drive, feel for shudder or jerky shifts when pulling away slowly, and listen for clunks in reverse. Ask if the mechatronic unit or clutch pack has been replaced; check transmission fault codes with a scanner.
In this diesel injection system, a short circuit in one injector wire can cut power to all injectors on that cylinder block, so the engine suddenly runs on half its cylinders. This is a known design flaw, not something a routine inspection would find, and it can lead to expensive repairs.
What to check. Perform an OBD scan for injector circuit codes (e.g., P0261, P0262), check injector wiring harness for chafing or damage, and test-drive to feel for misfires under load.
Expensive EDC gearbox repairs (clutch pack/mechatronics unit)
Found with a diagnostic scan
Repairs to the EDC gearbox, particularly the clutch pack or mechatronics unit, are costly due to specialized components and labor requirements.
What to check. Check for any history of transmission issues or error codes related to the EDC gearbox. Listen for unusual noises during gear shifts and verify if the vehicle has undergone any transmission repairs.
The 1.2 TCe (H5Ft) engine is known for higher-than-expected oil consumption, which can lead to engine damage if oil levels are not maintained. It also has a reported issue with premature timing chain stretch, causing noise and potential failure. These are chronic issues specific to this engine.
What to check. At viewing, check the oil level (dipstick) and look for oil top-up receipts or service history indicating frequent oil additions. Listen for a rattling noise from the engine on cold start, which may indicate timing chain stretch. Also inspect for oil leaks around the engine.
The 1.2 TCe (H5Ft) petrol engine used until 2018 is known to suffer from premature timing chain stretch. This can cause engine misfires or even complete engine failure if not repaired. Replacing the timing chain is an expensive job, so buyers should be cautious.
What to check. At the viewing, start the engine from cold and listen for a rattling noise from the front of the engine, especially in the first few seconds. Check for any engine warning lights, and look for service records showing a timing chain replacement.
Turbocharger and brake/suspension wear in performance versions (RS, GT)
Found with a diagnostic scan
Performance versions (RS, GT) of the Megane IV place additional stress on the turbocharger, brakes, and suspension components, leading to accelerated wear and potential failure.
What to check. Inspect the turbocharger for leaks, unusual noises, or excessive oil consumption. Check brake pads, rotors, and calipers for wear. Test the suspension for uneven handling, clunks, or excessive play in bushings.
dw5 1.2 TCe oil consumption and timing chain stretch
The 1.2 TCe petrol engine used before 2018 can suffer from excessive oil consumption and premature timing chain stretch. If not checked, these issues can lead to serious engine damage and expensive repairs.
What to check. Check the oil level and condition, look for blue smoke from the exhaust, and listen for a rattling noise from the timing chain area during a cold start. Verify service history for regular oil changes.
The dual-clutch gearbox on the Megane 4 may fail to engage 1st gear, forcing the car to start in 2nd. This indicates a chronic mechatronic or clutch fault that can be expensive to repair, and is specific to this gearbox type.
What to check. Test drive from a standstill to confirm 1st gear engages. Look for shuddering, delayed engagement, or warning lights. Consider a diagnostic scan for mechatronic error codes.
Chronic oil misting around DW5/EDC7 transmission plastic pan
Noticed on a test drive
The DW5 dual-clutch transmission has a known issue where oil vapor seeps around its plastic sump pan, causing chronic misting. This is a specific weakness of this gearbox, not a generic problem. Over time it can lead to oil loss and potential transmission damage if ignored.
What to check. At the viewing, park on a clean surface and after a short drive check under the car for oil drips or mist around the gearbox. Examine the plastic pan and surrounding seals for oily residue. If possible, raise the car on a lift and inspect the transmission pan area for fresh oil.
DW5 plastic oil pan seepage causing gradual oil loss
The DW5 transmission's plastic oil pan often develops seepage, letting oil escape slowly without leaving puddles. Over time this can drop oil level and risk gearbox damage. You may not see a leak on the ground, so it's easy to miss.
What to check. Check underneath for oil residue or weeping around the transmission oil pan. Look for signs of oil smell or low ATF level on the dipstick. If there is any seepage, budget for replacing the pan gasket or the pan.
The 7-speed dual-clutch transmission in Renault models can develop a shudder during the first-to-second gear change, often due to clutch wear or calibration issues. This can lead to expensive transmission repairs if not addressed. Buyers should be aware of this specific failure mode.
What to check. During a test drive, repeatedly accelerate from a stop and feel for any shudder or vibration during the 1-2 upshift. Check service history for transmission oil changes and any clutch adaptation procedures.
Early EDC dual-clutch transmissions (pre-2020) in this model are known to jerk when shifting from 1st to 2nd gear. This is a calibration issue that was improved in later software. Buyers should test this specifically during a test drive.
What to check. During the test drive, do several slow starts from a complete stop, gently accelerating. If a noticeable jerk occurs on the 1-2 upshift, it may indicate the early software or clutch wear. Ask if the transmission software has been updated; a scan tool may show clutch adaptation values or stored codes.
Early versions of the dw5 EDC dual-clutch transmission can feel jerky when shifting from 1st to 2nd gear. This is a known drivability issue that later software updates mostly fix. A test drive is the best way to check if a specific car is affected.
What to check. Take the car on a city test drive and pay attention to the 1st-to-2nd gear change. Ask the seller about the transmission software update history. If possible, compare with another car of the same model with updated software.
These reports come from the pages linked under each item: owner forums, repair guides and workshops. They are not a diagnosis of any one unit, and a careful check of the one you are buying still applies.
Text from the Kriko Cars catalog, version 0.1.4, under the CC-BY-SA-4.0 license.
