2024 x15 ticking at 1400 rpm

[JimT]

So if no one has checked the valve adjustment, that would be my first step. It's fairly simple. Also check the jake rockers for proper clearance too. All the service info should be easily available from quickserv.

Edit:

On the flip side, if all emissions systems are intact it's possible the noise is related to an EGR ratio commanded by the ECM. This could explain why it comes and goes sometimes. Not sure how one would diagnose this, but at the very least you could make sure all the sensors and wires are properly physically connected and working/reading correctly (monitor sensor data via insite). This is based on my understanding of EGR changing the characteristics of combustion and therefore the sound, specifically a ticking sound, that you might be hearing. If my understanding here is wrong I welcome correction.