upgrade oil to synthetic. try oil additive such dura lube. try the sludge remover formula first. if this helps than make a point of using oil additive conditioner every third oil change. just a suggestion.
Some oil consumption in vehicles is normal. If you do your own oil changes, I would suggest adding a cup of kerosene to your oil right before you change it next. After you add it, just run the engine at idle until it is warm (this will help remove sludge and deposits). When you change it use a good quality motor oil of proper weight per the ownwers manual. Might even want to try the heaviest they recommend.