How can excessive camshaft lobe wear be detected without removing the cam from the engine?

Using the push rod travel on each cylinder to detect excessive camshaft lobe wear is a viable method because it allows for monitoring the lifter's ability to push the push rod in response to camshaft action. When cam lobes wear down, the height of the lobes reduces, which affects the distance the push rods can travel. This change in push rod movement can indicate how much wear has occurred on the camshaft lobes without the need to remove the cam from the engine.

By measuring the push rod travel from one cylinder to another, you can discern inconsistencies that may arise due to uneven wear. This method is practical because it utilizes existing components and does not require the labor-intensive process of disassembling more significant engine parts.

The other options involve approaches that either require removing parts (like the timing cover) or do not directly correlate to diagnosing camshaft wear effectively. While measuring cam lobes with a micrometer provides precise data on wear, it cannot be done without removing the camshaft itself, contradicting the question's requirements. Similarly, using a dial indicator on the cam after removing the timing cover is another method that necessitates disassembly. Lastly, while inserting a feeler gauge is useful for checking clearance, it doesn't specifically