Bobcat s590 low oil pressure

[L.mpavingandconcrete42.lm]

Hi all hope someone can help me I have a bobcat s590 engine is a kubota v2607 oil pressure is low starts up 30 seconds later shuts down so I changed pressure sensor still shuts down but sounds good when running so I pulled the dip stick to check level of oil while it was running to see if it had dropped hasn't moved from full so I shut it down I then take filter off no oil inside only residue no metal inside but. So I decided to start with filter off no oil comes out so I pull pressure switch no oil out of there either but is still not rattling