Our situation with my wife's 2011 Dodge Nitro 114,000 miles is that it is been running poorly and sometimes refusing to start. Check engine light on. Engine codes are cylinder 3 misfire permanent and multiple cylinder misfire permanent. Removed left side valve cover. I was hoping to see a rocker arm fallen off because of a bad lifter, but unfortunately I didn’t see that. Valve cover: Has water mixed with oil deposit at rear of valve cover. Looks like brown cream. Otherwise valve cover is clean. Rocker arms: still in place. I had my wife turn over the engine while I watched. I could not see any dysfunction of any kind in the rocker arm movement at any of the left side cylinders. This included exhaust and intake valves. The block is cast-iron, but the cylinder heads are aluminum. I’m starting to suspect a cracked cylinder head at number 3. Although I don’t understand why that would create a creamy deposit at the back of the valve cover rather than directly above number 3 valves. My plan was to replace the lash adjusters/lifters for number 3 cylinder. Because there doesn’t seem to be much problem with my current lash adjusters/lifters I’m looking for advice on what might cause the misfires and the brown creamy sludge at the back of the valve cover. The valve cover has no PCV hole, breather hole, or oil cap hole or hole of any kind to let in water from the outside. #3 compression Test 125psi cold. Coolant system pressure test 16psi cold, no pressure loss. Thanks all members for any advice.