Problem or run around?

OK if there is't oil on the intake side then check the exhaust side for oil in the manifold. Otherwise check the return side of the oil galley for actual return volume . The oil only lubricates the bearings so should return the same as it is supplied. Last thought is being over pressurized . What kind of oil pressure you running? One extra thought. what kind of lines are you using? ridgid of flexable? might be a prob with the flexable type internally