Re: 4.2 slow oil leak - bottom of oil pan wet with oil
How much oil do you add say within 1000miles? A 'drop' to me isn't noticeable as my driveway would soak that right up into the pavement and I'd never know!
If you have the means, jack up the front end (place on axle stands in appropriate place), and check around the oil pan for a gasket leak. It starts out slow and can increase without much warning. My taurus had that problem and it was so slow and a few weeks later I put half a quart of oil in every second day (only drove 17miles a day!) and found out that it was the gasket. If it was a valve cover gasket you can check the front, and the rear by removing the cowl (as if you were to replace the spark plugs). It's easier to check the valve covers than under neath, but I'm sure the problem lies somewhere underneath. It could even be something as simple as an oil filter that's tight, but wasn't threaded properly so the seal is a bit loose in one area causing a slow leak.
Another thing you can do before checking for leaks is to add some UV dye to the oil. Don't add much of course, but it is available at auto part stores. If you have a trouble light, buy a UV bulb and you'll be able to narrow your search much faster.
'00 Durango R/T 360ci 290hp (modded); 138,500m
'06 Pontiac G6 GT 3.5L 220hp; 44,000m
'12 Chrysler 200 Limited 3.6L 283hp; 13,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!