Take off the rocker arm cover and the rocker arm shaft assemblies in the Ford Escape hybrid. Tighten the lash adjusters by lifting them slightly and placing a rubber band on respective lash adjusters so that they do not fall out of the guides while being tightened; in case a lash adjuster drops off, place it in their respective guide. Take out the hydraulic lash adjuster guide assembly and thereafter take out each of the hydraulic lash adjusters from their holes, the arrangement of each lash adjuster must be the same as that of the bore it was removed from in order to be reinserted into the same location. Do not invert lash adjusters as this can admit air into them and this will call for bleeder. With this lash adjuster in the bore, apply a downward force on it to see if it shifts; if it does more than 1mm, there could be trapped air. If you think air is trapped, tighten the rocker arm and its cover and purge air from the lash adjuster for 10 minutes by advancing the engine and adding no load at 1,000 rpm. Then, take out the rocker arm cover and the rocker arm back and forward to listen for air; if air is present, replace the lash adjuster. When the lash adjusters are taken out, check for wearing signs on them. After the inspection is complete with the lash adjusters and other components, return the lash adjusters back to their bores, put back the rocker arm shaft assemblies and the rocker arm covers.