Loss power


#1

My 96 suburban has lost power. I have checked the compression and its is at 150 except 4 and 5 at 120. It sucks air in though the valve cover. Any ideas except rebuildingg engine


#2

Post the engines manifold vacuum readings,unless you are done with diagnostics and are sure the engines loss of power is related to a mechanical condition,do you feel the “sucks through valve cover” is a sympton of a worn engine condition? Are you looking for a way to raise the compression on those two low cylinders?How low is the power?