is the issue that your lifters are sticking? Try running a can of sea foam or marvel mystery oil prior to an oil change to clean up any sludge. Another way is to use Mobil1 oil, which contains high detergents and will clean sludge out. Beware though, if you have lots of sludge and start using synth, you should expect to do some frequent oil changes as the oil will darken need replacing faster than normal.