Use purple Loctite, not blue. It's designed to work better with small-diameter screws like the valve cover and side cover hardware. Make sure the threads are clean. I use spray brake cleaner and an air hose. Loctite will not bond to an oily thread, male or female.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!