Scrape excess engine oil from your boots using a spoon. Wipe the oil onto a paper towel and continue to remove as much as possible. Discard the paper towels in a sealed trash can.
Pour talcum powder over the remaining engine oil stain until it is completely covered. Allow the powder to remain on your Timberland boots for 15 minutes to absorb oil residue.
Vacuum the powder off using the hose or upholstery attachment for your vacuum cleaner.
Pour 2 cups warm water into a bowl. Add 1 tablespoon each of dishwashing detergent and white distilled vinegar. Mix the ingredients together.
Dip an old toothbrush in the soap and vinegar solution. Allow excess moisture to drip back into the bowl. Scrub the nubuck suede surface of your Timberland boots to remove the remaining engine oil stains. Rinse the toothbrush with water, as needed, apply more detergent solution and continue to scrub.
Moisten a clean cloth with water. Blot the surface of your Timberland boots to rinse them and remove the detergent.
Press a dry cloth against the suede to absorb excess moisture. Allow your Timberland boots to air-dry completely.
Brush the nubuck suede surface of your Timberland boots with a suede brush to raise the nap and blend the fibers.