Do you have one of those cameras that hooks to your phone that you can look into hard to reach places with? If you do, you could drain the oil and use it to look and see how close to the pan the pickup is, or if maybe it is clogged. Those cameras are supposedly pretty cheap at Harbor Freight.
I used to have one, but it stopped working. Might need to get another. When I changed the oil I tried to shine a flashlight in there, but it was impossible to see anything.