Well for starters its a 97' Caviler with the 2.2 ohv and the problem is that the nuts on the valve lifters came lose, i looks like its happened before because one of the others are double nutted. Should i just retightin the nut, what are the toque specs and should i just use two nuts like the other one?

sorry about the gramer I am not from the U.S. and i barley speck English.