MudChucker wrote:
do you have an enclosed under side ? any signs of moisture ?
the vents are usually one long sleeve along the floor, if you have a smell at one and not out the others, perhaps you have a dead critter in your vents ?
we had a baby wipe problem in a past 5ver and the smell was being sucked back into the trailer as we drove... was nasty.
after cleaning the black tank - removal, pressure washer etc etc reinstall I proved that there was no leaks by dumping an entire bottle of orange pine sol in the tank and waiting a few days to see if I could smell it anywhere but the roof...perhaps you might consider dumping and rinsing your black tank and adding some strong scent to it and then wait and see if you can smell it any place...
Its a closed up undercarriage. I see no signs of leaking.