Is it losing oil or water? Does it smoke while running or on start up?
I'm thinking it's condensation or water running through the pipes and spitting dirty water on your trailer more than oil. If oil is running through your headers it should be smoking a lot. You will probably end up pulling the head for seals and a new gasket, that should fix it, and have it checked for cracks.
On my 86 Vette, the PCV was pulling oil and dumping it to the egr, then the oil ran into cylinder 6 and kept fouling the plug, didn't figure it out until I did an injector swap and pulled the intake apart. Problem was aftermarket non-baffled valve covers and PCV in rear of engine.