does locktite go bad?

hey guys
ive been dealing with two bolts which keep loosening up after a few heat cycles
(they are the bolts that hold the thermostat housing on my 351 in place)

the intake is a cast aluminum eddie, and the water neck is also aluminum but the bolts are who knows what, whatever i had laying around

last time the bolts came loose i put some blue loctite on there and sure enough, it came loose AGAIN
i put it back together with a split lockwasher under each bolt and copious amounts of more blue loctite
now, i did notice the loctite seemed thinner then i remember it should be

is loctite an emulsion that can separate?
does it go bad?

or am i using the wrong product here?

or is this just bad yuyu for buying a blue oval?