Get off the computer and run for your life.
You need to have it drained out.
You need to have the radiator flushed immediately
You'd need to drop your fuel tank and drain it out.
The petrol engine will just not run. No damage will be done. You will need to drain the tank, flush the fuel lines, and replace the fuel filter.
Ford: 7.3 diesel fuel getting into the radiator
Made mistake of pouring wrong container in radiator
how you put on radiator for a Hynudia xg 300
You stand a chance of being fined if the authorities catch this fuel in your auto. The chance of them finding out are not good, unless you have an accident, although the fines can be very large.
Where is the radiator to put fluid for 2001 jetta?
See saturnfans.com Barnowl posted a home made procedure for radiator flushing.
You don't put water in your radiator, you put antifreeze.
If you put petrol in a diesel vehicle do not start the engine. Petrol will do serious damage to a diesel engine. You must drain all the petrol out and flush the fuel lines.