I don't understand the question... what is an "old scan"?
I scanned 70 year old pics and letters from my dad’s time in the war. Because they’ve faded a lot with time I purchased a fairly good scanner, however, when Premier Elements renders my scans it compresses the images to the point where they are more blurry than the scan. Can’t I turn off the compression, or is their an upgrade I could purchase which would allow me more options?
Please confirm what version of Premiere Elements that you are working with and on what computer operating system it is running.
What are the pixel dimensions of these scans? And, what format are they in...high quality jpg, tif, or other?
What are you or the project setting as the project preset for the project into which you are importing these scans?
How do you intend to export your Timeline content?
Let us start here and then decide what next.