My Ram just turned 200k miles and has developed a leak near the crankshaft seal. However I can't determine if the oil pan is leaking or the crank seal because it doesn't do it in the driveway, only when driving. It's losing @ 1/8 to 1/4 of a quart at a time. Any suggestions to pin it down?

 

Front, or rear?

 

Front. Always had normal oil changes, never had a leak until I sent the wife a pic of the odometer turning over. I'm meticulous about keeping up on the maintenance so it surprised me when it suddenly started. I've cleaned the front of the engine a few times now and like i said in the driveway nothing. On the road when I get to work I have oil dripping after about 7-10 miles.

 

Change the front crank seal. It is inexpensive, and "easy" (as these things go.....)

 

Have you ever replaced the PCV valve ? I would at least check it an make sure its not gummed up , One job of the PCV valve is to reduce crankcase pressure. A PCV valve that is clogged or stuck in the closed position will allow crankcase pressure to build . This can cause the oil to leak through gaskets and seals. It can also force oil into the air cleaner assembly.