Searching A Column For A Word And Deleting All Rows That Don't Contain It

I am trying to create a search function in a database I have made. I have a userform with drop down boxes that people can choose what they want to search for. Once they have chosen and clicked the search button I want it to search only in the relevant column, i.e. search for the word in the dropdown for "engine" only in the "engine" column of the database. Once it has found the appropriate cells with the answer, I want it to delete all other rows that don't include the answer.

Once it's done this it needs to do it again for the other fields, unless they are empty. I have used 'If engine_type <> "" Then' as the starting point so that it only searches chosen fields.