hose poping off left to right!...HELP PLEASE!!!

[fockviz]

i have a 99 540i and its acting up...problem - theres a knocking noise from the engine compartment...i got it serviced at the dealer..they say its normal and its just some vavle purging..but its annoying...and the radiator hoses that you can can see from under the hood...it poped off when i was driving...i reconnect it with a hose clamp that has the adjustable scew....then it starts the other end of the hose pops off.... then another..i also got it serviced and the dealer...they cant find the problem..they said my water pressure(or something about the radiator pressure?) is fine.can someone tell whats wrong....i changed already 3 hose clamps...please help.. thank you for looking