Good day I have a 2000 Renault Clio 1.4 8v. The vehicle has approx 83000km on and the top gasket was replaced on 80000km. For the last two weeks the vehicle just suddenly start to***** and then after depressing the clutch it would cut out and struggle to restart, about three tries. I checked the plugs and found them to have a black deposit, so I cleaned them off and replaced them, no success. There is a light oil deposit in the aircleaner box, the oil cap is clear of any deposit and the water is clear. This problem is not continuous and happen only from time to time. When idling the revs keep dipping. Would you be able to help me, as I'm afraid of just taking it to the dealer and being told the whole engine need to be replaced etc.
I have no repair information for Renault vehicles. However, the oil deposit in the air box sounds like a bad PCV valve. It should be mounted on the top of the valve cover (where the recent gasket change was done) and has a hose going to the airbox. Run some injector cleaner through the tank to make sure the injectors are properly atomizing the fuel, allowing for complete combustion. Make sure the timing is properly set, also. Make sure all 4 cylinders are receiving a strong bluish-white snapping spark. If the valves are adjustable, make sure they are properly adjusted.