Can the source of funding change once we have i20 form?

I had a question related to funding and i20 form. May be answered previously, but please respond if here if you have any specifics.

Let's say to get the i20 form from the college, I show personal funds (enough to cover first year expenses). But when I go for visa interview process, can I change the source to an education loan? Will the visa interviewer not like the fact that my source was different when I requested i20.

I was planing to use personal funds to get the i20 quickly and get the visa process started, as it seems getting an education loan is going to take some time.