During a cylinder balance test, which of the following scenarios would suggest a connecting rod issue?

In a cylinder balance test, the key objective is to assess the performance and contribution of each cylinder to the engine's operation. If disabling a cylinder results in a decrease in noise, it indicates that the cylinder is not contributing to the overall engine noise, which can suggest that the connecting rod or its associated components in that cylinder might have a problem. This could mean that there's an issue with the connection between the piston and the crankshaft, possibly creating excess play or improper alignment.

When noise diminishes with the cylinder disabled, it suggests that the noise is emanating from that particular cylinder's operation or its mechanical connections, which could point directly to a malfunction in the connecting rod or its bearings. Such issues can lead to serious engine damage if not diagnosed and repaired properly.

In contrast, other scenarios, such as a noise increasing when a cylinder is disabled, might indicate problems elsewhere in the engine, perhaps related to engine balance issues or other components, but not necessarily focused on the connecting rod. Excessive clearance in the pistons or a smooth running engine at higher RPMs would likely reference different issues altogether rather than isolating a connecting rod problem during a balance test.