Re: 2004 Jeep Grand Cherokee no compression cylinder #1, with knock
Not familiar with this engine myself, but according the manual the camshaft is pressure lubricated via oil galleries, so any clogging in the head would not prevent lubrication of the camshaft. Oil is fed to the hydraulic lash adjusters and from there goes through the hollow pushrods and lubricates the valve train. The oil then drains back via the pushrod guide holes to the pan. Which hole(s) where plugged in the head?
The formation of sludge points towards a bad working PCV system and/or lack of the required oil changes. Plugging of oil canals will destroy the engine sooner or later.