I have a 1988 Dodge d100 with a significant oil leak coming from the rear of the motor above the oil filter. It is so high up I'm not sure where it is coming from. Any ideas?

 

Valve cover gaskets? Rear intake seal? Oil pressure sensor? Lots o' stuff up top that can puke oil.

 

i would toss a 2nd vote on the valve covers gaskets especially if the truck has spent a lot of time sitting. they always start leaking eventually. i replace the one on my 81 less than 7 years ago and it started leaking again a couple of years later but has started getting real bad lately now that i drive it a lot more.

 

Look at the back of the intake where it mates with the block. If it has cork gaskets it's guaranteed to leak there. Valve covers are the second on the list.