To drain the fuel from a W Reg Renault Scenic, a person might have to have the tank removed and drained that way. Most newer vehicles have anti-siphon mechanisms inside the gas filler tube to prevent people from stealing gas.
Yes you can use Siphon but next time try reading the label and don't put in diesel.
Siphon it all out. Petrol (Gas) and diesel mix incredibly well so it is impossible to siphon off just the petrol, you need to remove the whole lot and then full it up with diesel.Depending on how old the car/truck is, it will respond differently to having petrol go through it. Newer direct injection/common rail/turbo diesels will not like having petrol run through them at all, and might mean replacing both the high and low pressure pumps(Diesel acts as a lubricant for these and when petrol is run through them it washes all the lube away) and the turbo etc. Older diesels might get away with running a bit of petrol through them, but again it is recommended removing all the petrol and just putting diesel in.Even putting a small amount of petrol in a diesel tank will dilute the lubricating power of diesel and may damage parts.In short, when you put petrol in a diesel, grab yourself some hose and siphon it all out!
Use a siphon hose inserted into the tank. To get the remaining fuel out or if your vehicle has an anti siphon device you will have to disconnect a fuel line and turn on the key. This will activate the fuel pump and fuel will flow from the line.
Siphon out as much as possible and refill with deisel, keep topping up every time you use a gallon or so, I've done this twice and no damage to engine.
Almost every car made after the late 1970s has an anti-siphon barrier in the filler tube.
These come with an anti-siphon device built into the tanks, as most current production trucks do.
Accelerate real hard and don't stop You can siphon the fuel out. Sometimes it is necessary to remove the filler neck hose from the tank in order to insert a siphon hose.
Dump/siphon/drain it as best as possible and as long as you haven't tried to run it, you should be able to fill it with petrol and fire it up! The petrol will dilute the residue sufficiently.
Lift the back seat and undo bung on top of tank. Siphon it from there.
DO NOT ATTEMPT to start the vehicle. You must drain the tank (drop it or siphon it out). Then fill it up completely with the correct fuel. After you start it, you may experience white smoke....this should be temporary. I WOULD SUGGEST CHANGING THESE SPARK PLUGS AS THEY MAY BECOME FOULED AFTER THIS.
Current production cars typically have anti-siphon necks on the fuel tanks in order to both prevent fuel from being siphoned out, as well as to keep foreign material from going in.
Purchase a mechanical hand pump at almost any auto parts store. They are very inexpensive and safe use.