My daughter has a 2005 renault megane coupe petrol engine and only when you first start it it sounds like a 30 year old deisel engine then goes ok..any idea what this is and what is needed to fix it.
Maybe its a bit of mechanical clatter until the oil pressure has built up?
Make sure it has a genuine oil filter, and that the oil is of the recommended viscosity.
John
Whatever position a 4 cylinder engine stops in, there will always be some valves open. The pressure of the valve springs tries to squeeze the oil out of those tappets. When you re-start the engine, the 'dry' tappets rattle until the oil in them has been replenished, taking up the clearance.
Does the clatter only last for a few seconds then only happens again the next day when cold again? If so then this is an issue with the inlet cam de-phaser valve/actuator, rather than a conventional cam pulley you will have an oil controlled actuator and when cold this will clatter for a second or 2 then shut up usually for the day.
It will need a new cam pulley/actuator which is not cheap or easy fortunately.