Uneven / Eratic Idle and White Smoke

[baby2bubble]

Hi, new to the site and need a bit of advice.

My cousin has a Megane 1.4 and it recently started becoming rough. There were a white smoke coming from the exhaust which smelt of burning, the revs were sitting very low but still drove ok. It was losing oil weekly somehow. So, after checking the air filter, I did a minor service and found the oil and air filters in a bad state so cleaned them up and replaced the filters. Filled the engine with new oil and she says it ran better. But I still found that it was 'shaking' inside.

Then she said it wont drive up hills or go much at all. I checked the coils and 2...yes 2 had gone so Ive just replaced all 4 coils and spark plugs. The plugs were in a bad state too. It now drives fine however the initial problem is still there.

Struggling to keep a constant idle and puffing light smoke out the back and the car revs on idle. Having looked at the obvious and taken car of them, what could the other issue be? I was thinking idle control valve? I have no experience with Meganes or Renault engines but can work around it.

But I was thinking, why would it be blowing white/clear smoke out of the back of the car? Does it just need a bloody good run now theyve been done or have I missed something? Or is it more serious?

Any help will be much appreciated! She doesnt want to get rid of the car and seems happy driving it around now but I know 1 problem will most likely lead to another so would like to try and get it sorted.

Cheers

[ChrisM]

How is it doing for coolant? whaite smoke and irratic idle some times points at head gasket, if possible maybe a compresion test just to make sure.
White smoke could also mean she is running really lean, have another look at plugs they may show signs of white chalky type material if so it is lean, if plugs are just like when fiteed could be H/Gasket washing the plugs with liquid.