oh dear.i did the same in my new diesel merc.as mentioned if only small amount like mine then top up with diesel and will be fine.engine damage is rare but fuel pump can suffer due to lack of lubrication from the diesel.sometimes the seals in the fuel pump can fail after a period of time,maybe a year or more.i dont wish to scare you but that can happen and can be expensive to fix.but a garage is best to change fuel as there is no way of disposing of it.on a good note wagon drivers use to add petrol to diesel to give the engine a boost
mike
February 2009