Hi there I have Renault megane 2006 1.6L 16v 1 >> when i engage (D) the rpm is normal and no porbelm then i start acceleration and then release it the rpm remains above 1 for while like 10sec more or less and then goes down to normal(sometimes not and remains high) and if i change the gear to (N) because the engine sound very loud the rpm goes up to 2.5 or 3 and then goes down to normal under 1 2>> when i D-accelerated i feel that the gearbox is shaking under my foot 3>> i have connected it to a diagnose computer and sometimes it says A/T converter and sometimes not and i don't know where it is??? and is it the reason or problem throttle ??? thanks in advance

You have a problem with your auto gearbox.check you auto box iol level.

Hi

The A/T converter is also known as the torque converter, you can often tell if this is shot / failed if when you put the car in drive with your foot off the break the car will creep forward and drive by itself, in this case more often than not it is the Torque converter and again more often than not they do tend to go on Renaults around 50 to 70k miles.

As for the odd idle speed this again can sometimes contribute to the first fault. although if the car is not creeping forward and changes gear well then it could be the air mass sensor also known as the MAF sensor.

Have the fluids checked in the auto box and also if you are paying a garge ask them to bleed the system through and check the slave cylinder for leaking air in etc.

Hope this helps
Regards
Dan