Service function guideEngine Noise Diagnosis

This guide teaches you to separate lifter tick, rod knock and piston slap by ear, by location and by measured behavior, so you can stop guessing and start testing. It explains how the valvetrain, connecting rod bearings and piston-to-bore clearance each produce a distinct noise signature, and why those signatures change with temperature, load and oil pressure. You will work through a cold start observation, a cylinder cancellation test, an oil pressure check and a mechanical inspection sequence that narrows the fault to one of the three conditions. By the end you will be able to classify the noise with confidence, document your findings and decide whether the engine needs adjustment, repair or teardown.