Oil leak and Dirty Coolant

I noticed on my way back to PA from CT that i developed an oil leak about 3 weeks ago. I lost 1 quart of oil on my 8 hour trip. I recently(as in last saturday) did an oil change and discovered that i had over tightened my oil filter. I believed that this was the problem and it was solved. Today i checked my oil level due to me driving back to CT tommorow and it has still leaked almost a half a quart in the past 5 days. The leak is in the oil filter, oil pressure sending unit area but i cannot pinpoint it. The block is dry from the valve cover gasket to the head gasket and wet from there down to the starter and there is oil on the control arms and down the side of the unibody like it is spraying(i think this is from the oil filter being over tightened). When idling there is no visible leak it only seems to happen when to motor runs for a prolonged period of time say 40min or more. I checked my oil line to my pressure guage but it is not leaking there, i still have 20psi at idle and 50psi at highway speed(roughly 2000rpm) At 209,000mi i expect that the oil pan gasket may need to be replaced along with the valve cover gasket and possible the rear mail seal but i don't know how to find this leak.

I also checked my coolant level, all seems good but it seems like i have mud or dirt in the system, what is the easiest way to flush the system and not just drain it?

Common areas of oil leaks on the 4.0 are the valve cover gasket, rear main, and the o-rings around the oil filter adaptor. Clean everything as best you can and then run for just a bit and look for evidence of leaks.

If your coolant looks dirty/rusty, definitely FLUSH the system, not just a drain and fill. Use the SEARCH function for more information on this procedure. Some people use a chemical flush for tough jobs; there are pros and cons to that. Good Luck!

Ah-yes all of the bolts on both my valve cover gasket and oil pan were between 1 and 1.5 turns loose! might be all set now that there all snugged up.