Hi I have a '98 megane RT 1.6 petrol, the engine is having issues

check spark plugs and wires.

sounds like its sucking in to much air at inlet manifold have it looked at

could be fuel starvation when changing over from one fuel to another.end of one/start of another,especially when engine cold and running on richer mixture .answer is only change when car is at normall temp.sorry but this is in the gas convertion manual....

this exact problem on a megane coupe is caused by a small air pipe that connects to a 2 inch wide black box that is located under the bonnet near the windscreen on the passangers side. the zigzag light indicates an electrical fault (in this case lack of compression and will affect your revs) if you find this pipe and it has snapped off. the reason for this may be that your engien is lose and moves. grab the engien with 2 hands and see if you can wobble it with allot of play. if so your engien mountings need replaceing. you may also experiance juddering in low gears

Having exactly the same problem with my megane and the mechanic just charged me £687.00 and does not know what to do!!!

this exact problem on a megane coupe is caused by a small air pipe that connects to a 2 inch wide black box that is located under the bonnet near the windscreen on the passangers side. the zigzag light indicates an electrical fault (in this case lack of compression and will affect your revs) if you find this pipe and it has snapped off. the reason for this may be that your engien is lose and moves. grab the engien with 2 hands and see if you can wobble it with allot of play. if so your engien mountings need replaceing. you may also experiance juddering in low gears

Check oil and coolant have thermostat checked it may be stuck. Do you have an ASC or ABS light on in the gauge cluster?

if this is an auto gearbox change the transmission fluid

try cleaning the petrol cap. it breaths round the key hole. i boiled mine. sometimes if there is not enough air in the tank. pure fule goes into the carb. and makes the car race. take fule cap and boil it in water. you can use steradent in cold water if you prefer. muck gets stuck in them.
liz.

the canister fuel filter is partly blocked. you will find it under the car at the rear . it is an easy fix . take off fuel cap . it is an inline filter only 2 clips to undo .replace with new one which costs about 10 pounds when you see new one you will see how easy it is to do