A valve cover gasket will solve your problem. It is an easy job but you have to be careful torqueing the bolts back down or you will be doing this all over again as it will leak. The cover bolts only have to be torqued to 11lbf/ft (15Nm). There is a sequence also. I don't know if I can describe it for you but the first bolt is the one on the right side at the front of the engine. Bolt 2 is the first one one the left side of engine. Then 3 is the next one on left side. 4 is the last one on right side and then bolt 5 is the last one on left side on cover. The left and right are as you are looking at the block. So starting at the front of the block it is right, left, left, right, left. If you really want to do it right gradually tighten them down. So first 3Nm, then 6Nm, 12Nm and finally 15Nms. One final thing. For the really anal you should undue the bolts in the same order listed above for tightening. Good luck.
1985 230TE 5spd