Rough idle and engine vibration

[anthonyb]

Hi all,
The car is a 55 plate 1.4 16v petrol megane mk2.
I have an issue with rough idling where I try to start the car, most of the time it is not always successful and I have to start it 2 or 3 times for it to fully fire up. When it finally does I get a very rough idle where the engine vibrates quite violently. This doesn't always happen when I first start the car, if the car has been parked but idling for about 5 mins or more then the vibration starts. Its not a regular or rhythmical vibration and sometimes more violent than others.
I have had the car in for a service about 1k miles ago and they changed the spark plugs and changed the oil. I have changed all 4 coils within the last few days but this did not have any effect.
See this video for the rough idle: https://www.youtube.com/watch?v=GcNr8robFEM
Pleeease help.

thanks
Ant

[Alz]

Hi I have same problem I have megane mk2 1.4 16v
2007 I haven't changed plugs or coil pack or serviced yet did you find a solution?

[anthonyb]

Hi,
Yes I think so. I cleaned the TDC/Crank sensor. The sensor looks like this: http://www.ebay.co.uk/itm/TDC-Crankshaft-sensor-Renault-Laguna-Megane-Scenic-1-4-1-6-1-8-2-0-7700101970-/221022880906?hash=item3375fd848a part number: 7700101970.
The TDC sensor is on the right side of the engine and to access it you have to remove the battery, ECU and slide the tray forward. Its pretty easy but takes about an hour and requires a 10mm socket to remove the 2 bolts holding it in place.
Its best to get a new one as the renault one tends to fail. I just cleaned the metal tip with WD-40 and it has made the car a whole lot better. I have not completely fixed the rough idle because I need to get all new engine mounts but this helped a great deal.
If you want to test your spark plugs just remove them one at a time and then replace it before moving on to the next one. you should hear the engine tone change and see a visible change in the engine movement if the spark plugs and coils are working.
Thanks
Ant