engine Judders at idle but goes away while driving

2004 RENAULT MEGANE
90,000 MILES • MANUAL
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TONY HANNON
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  • 1 POST
My car has developed a judder at idle that vanishes when driving, which is replaced by an engine warning light whilst driving. This light vanishes as soon as idling. Mechanic friend disconnected coils from under car to test for bad one which he located.

Which coil part is this that I need to replace? Wish to order part but money is tight so do not want to order wrong component.
Dec 5, 2016 at 10:59 AM
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STRAILER
  • ✓ASE Certified Mechanic
  • 54,832 POSTS
  • ASE Certified Mechanic
Hey Tony,

I would replace the spark plugs first as these can cause the coils to malfunction. Next, runs the codes to see which cylinder it is and then replace that coil if needed, then clear the codes to recheck the system.

https://www.2carpros.com/articles/how-to-change-spark-plugs

and

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

and

https://www.2carpros.com/articles/check-engine-light-clear-codes

Please let us know happens so it will help others.

Best, Ken
Dec 10, 2016 at 1:24 PM
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