I just acquired an '84 Dodge Ram50 TD (with the Mitsu 4D55 engine) that has 92K miles, but questionable compression (allegedly ~300 psi) - so some engine wear. The previous owner parked it after a severe oil leak started 'under the timing cover'. He took apart some of the timing belt components and quit at that point. This owner suspects the truck has been neglected as far as oil changes and general maintenance.

I plan to reassemble the engine enough to start it and see where the oil is coming out. Having said this, is there a typical seal that fails in these engines, and could the oil leak be due to a plugged crankcase vent of some sort? How is the crankcase on this engine vented? Do these engines leak oil badly due to blowby when they get worn out? I have the Dodge factory service manual for the truck.

I'd like anyone's general thoughts on this.

Thanks - Steve