I’ve had things disappear before I’ve finished fighting off minions.
I’ve also had items from slot machines stay there for so long, I came back to see the machine had reset. The door was shut and the item was still floating there. I had left this thing there for a WHILE.
Farming bosses will leave the floor littered with loot, but when does it all go away?
Is there a set rule or do we just go back to the standart: RNG is RNG.
Not sure what the time is, but it is fixed. Also, leaving the map can clear the loot (without resetting crates etc). The timer seems to be shorter in TPS than BL2 - always running back after finally dealing with a mob, only to discover that everything has gone 
The time I left loot in a Slot Machine; I left Sanctuary, took and completed a mission, came back and it was still there. When I was farming Terra, I’d leave and re-enter. All of his loot was still piled up on the floor.
I wish it were as simple as that.
White items, money and ammo disappear relatively quickly. And they disappear the moment that you leave a map. Green or better items, and Eridium, stay around longer, and stay if you leave a map and come back (with something like a slot machine or Michael Mamaril, you’ll find the item just floating in the air). I think blue or better items stay around longer than green.
Anyway, for more info, here’s a thread in the old forums. Look for the posts from botman (from Gearbox) in particular. On the PC, you can actually change how long some items stay around by editing a file.
http://oldforums.gearboxsoftware.com/showthread.php?t=356628
Im pretty sure green or higher stay until you save and quit. Or atleast legendary anyways
Well I’ve certainly seen the items from Moxxi’s toy box in TPS just handing there in mid-air before! Good to know that higher level items hand around longer - now I won’t be so paranoid about missing out on something cool. One exception I do know about: if you happen on a Gwen’s head by Lynchwood Station in The Dust, do NOT fast travel to Lynchwood so you can sell gear to create space in your inventory - it will be gone when you get back, along with the box
FWIW, I have no idea how things work in BL:TPS, but I imagine it’s similar.
Interesting point about Gwen’s Head. I’ve probably seen that, but hadn’t thought about it. Now that you mention it, it’s kind of weird how the gun disappears with the box.
You mentioned Lynchwood station. You do know that the box spawns at various locations in Dust, right? I’m guessing that every time you enter the map, it’s there, somewhere.
Yep, was aware of that. The reason for specifically mentioning Lynchwood is that it’s where I lost my opportunity at one. I should have just driven over to the Dust exit and sold stuff there, but I thought “There’s vending machines right in the station and I’m standing right beside the travel point…” Big mistake.
I suspect the reason it disappeared is that the random box generation routine runs whenever you enter the map, clearing whatever was there before?
This is exactly the reason I just dump gear on the ground. I don’t normally see much need for money so it’s not really worth my time to run over and sell stuff. Especially if that means that loot will disappear.
I guess I’m just a little gun-shy about that.
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Happened to me, but in Borderlands The Presequel, i joined my friend switched some weapons, then after a bit, i come to equip the heartfull splodger, to find that it had disappeared. Can someone help me?
To answer your question: sorry but no - if it’s gone (either because it disappeared through the floor or you left long enough that the game item memory purge go it) it’s gone.
You could try posting in the relevant Pre-Sequel/Handsome Collection On-line Play and Trading section to see if anyone would happen to have a spare they don’t want.
Locking this now since the thread’s rather old and musty, and this is a bit off-topic for BL2.