ok, the usa car, or 1998 canada body
runs OBD2 ECU and needs Crank sensor. (will run with out but badly)
mine was oily too... but found out the oil on my 96 , came from... get this. it was going down the plastic flex conduit to the CKP sensor. the source leak was
valve cover, then to this silly conduit. to the bottom of engine where it dripped and fanned up to the pan front to rear.
the only way to find leaks is clean it all. then run it.
never seen a leak easy to find, just at a glance. ever. (rare)
there is gravity at work, and wind, and leaks do follow odd paths.
if you put a 95 engine in a 96 the first step is pan off old 96 and moved to 95 with CKP sensor. and matching pump. 3 parts. there.
unless running a stump puller, (off road only)??
here is the conduit leaking (flex split conduit 96)
http://www.fixkick.com/my96-16v/ckp-sensor.jpg
once all top leaks cured the conduit dried up and no more leaks.
most cars like this never get service, ever, never a Valve covers set. nor ever check lash while doing this..... so all get hard and leak, every one. do .
not only that?, it might just be the last engine owners mess , (remainders)
most pans never ever leak.
unless messed with, (the color of the RTV i think was orange new) if you see blue its messed with....or cork.
they were glued on, and can be heard to remove it was done so well.
rusty pans expected sure.