Cadillac Repair: lifter noise, oil residue, lifters

Question
hi i have a 96 caddy eldorado etc 4.6 before i had the oil changed i heard a ticking noise from the lifters after i changed the oil it went away 2 weeks later the noise came back and noticed i was a quart low on oil maybe they didnt fill it all the way i replaced the court and still have the noise this has happened before and went away. could it be posssible there is air in the system i was told that from someonethe engine has 54,000 miles on it what will cause this noise and should i replace the oil presure switch the car itself has 140,000 miles

Answer
That is normal oil usage for a Cadillac. You can purchase what is called LIFTER OIL which is supposed to clean out the old oil residue from the lifters. Sometimes it works and sometimes it does not. Give it aboy 2 or 3 hundred miles to see if it works a if it does not resolve your problem you will have to replace the lifter and I STRONGLY suggest that you replace ALL the lifters.