yes, it sounds to me like the thermal paste isn't right, or the heatsink is somehow hung up on something, keeping it from making good contact.
i use an index card, and i spread a nice thin layer over the entire top flat surface of the cpu, then carefully lower the heatsink on.
i don't know about that exact heatsink, but some have a notch cut into one side of them, and you need this on the correct side.
is it this?
if it is, then it has no notch.
90+ will kill a processor, AMD rates some of them at a melt point
of 90, and so if yours is still running at 90, then shut it off, and do whatever it takes to get that back down.
the siren noise is the overheat alarm.