While loud lifter noise is a symptom of a problem (usually insufficient lubrication leading to noisy lifters until oil pressure builds), it doesn't inherently create the conditions that trigger a knock sensor. The sounds are different and originate from different parts of the engine. Knock is a sharp metallic pinging or rattling; lifter noise is a more rhythmic tapping or clicking.
However, there's a *possible* indirect link:
* Severe lifter noise masking actual knock: If the lifter noise is exceptionally loud, it might mask the quieter sounds of actual engine knock, preventing the knock sensor from registering it initially. In this scenario, the problem causing the lifter noise (e.g., low oil pressure or worn lifters) could be allowing conditions conducive to knock to develop.
* Correlation, not causation: You might *observe* both lifter noise and a knock sensor code simultaneously. This doesn't mean the lifter noise caused the code; both might be separate symptoms of a more underlying problem, such as low oil pressure, insufficient oil viscosity, or even a failing engine component that leads to both noisy lifters and combustion issues.
In short: Fix the lifter noise (which usually involves addressing low oil pressure, using the correct oil weight, or potentially replacing lifters) and *then* diagnose the knock sensor code separately. They're likely unrelated but could share a common, underlying root cause.
