What tool is typically used to check cylinder head warpage?

The correct tool for checking cylinder head warpage is a dial indicator. This precise measuring instrument allows the technician to detect slight variations in the surface of the cylinder head, ensuring that it is flat and within the manufacturer's specifications. By placing the dial indicator against the surface and moving it across the cylinder head, any warping or unevenness can be accurately measured. This is crucial for ensuring a proper seal when the cylinder head is reinstalled, which is essential for engine performance and preventing leaks.

Using a micrometer, while it is a precision measuring tool, is more suited for measuring the thickness of materials or small dimensions rather than assessing flatness over a larger surface area. A feeler gauge, on the other hand, is typically used to measure gaps or clearances and is not designed to measure warpage effectively. A torque wrench is primarily used to apply a specific torque to fasteners during assembly rather than measuring physical dimensions or flatness. Thus, the dial indicator stands out as the most appropriate tool for this specific task.