Here's something you could try. Not sure if this will work, it's an old trick...
Drain your oil and change your filter but refill with NON Detergent oil. NAPA sells it. Then when you drive your car, try and run the rpm's up and down in one gear. If you know what I mean, "gear it". Rev it up and then let off on the gas. This might help get rid of any glazing of the cylinders and rings and hpoefully seat them. It's worth a try