is a renault megan 1.6e injection engine,exactly the same as the renault scenic engine

Yes, they use the same engines to save money.

the name is a big give away - renault megan scenic.

It is the same engine in both models, but only year for year. There are changes and modifications every year for most makers of cars in the UK, so a 2000 hatch engine may not be the same as a 2003 scenic and so forth