A technician records a leakage test with Cylinder 3 at 45%. What should be the next step?

When a leakage test indicates that Cylinder 3 has a leakage rate of 45%, it suggests an issue that needs further assessment to determine the precise cause of the leakage. The next logical step is to remove the oil cap and listen for escaping air, as this can help identify if there is a problem with the piston rings or if air is escaping through the crankcase ventilation.

This approach allows the technician to assess the type of leakage that is occurring without taking apart engine components immediately. If the air is escaping from the oil cap, it would indicate a failure in the piston rings or cylinder walls. Conversely, if the air is primarily escaping from the intake or exhaust valves, it might point towards issues with those components instead.

The other options would not provide immediate diagnostic insight in this situation. Replacing the piston rings is a more drastic step that should only be considered after confirming that they are the source of the leakage. Examining the fuel injectors and checking the ignition timing are important but not directly related to diagnosing the immediate problem indicated by the leakage test results.