2022 Tahoe engine tick (recording). Please help identify possible root cause.

[tahoe_rst]

If the leak were at the y-pipe then the frequency would be 2x crankshaft rotation instead of 1/2 crankshaft rotation as it currently is. If it's an exhaust leak, then it's at the exhaust manifold on a single exhaust port and wouldn't disappear with throttle.

Another clue that points toward a lifter and my theory is plausible, is that it goes away with throttle. Faster cam rotation = less time for the lifter to bleed off oil pressure internally = maintains lash at higher RPMs. Either way, I don't think it's a significant issue at this point. If it were mine, I would pay attention to it over time and see if it worsens. I doubt that failure is imminent.

I'm not "rooting" for anything - just trying to be helpful.

Thank you for your analysis Dave. I recorded one more video with hot engine: I put a phone under the engine and revved it. Now I can hear in the recording that ticking noise is not going away completely when you rev it.

 

[tahoe_rst]

It's hard to tell, but it sounds similar to an exhaust manifold leak to me. I do hear the internal stuff as well. I know on my 17 I can hear injector and normal valvetrain operation. You said it goes away with throttle? Have you tried to brake torque it with a little throttle in gear and see if it changes sound?

Thanks for comments, yes, I tried slight throttle + brakes today - sound doesn't get louder (as far as I could hear).

 

[ZKWBQD]

Hi all,

My new Tahoe 6.2 engine ticking, less than 2k km mileage.
Those who had experience with lifters, HPFP, etc, please help me to diagnose it.
I would like to understand if that is something I should be worried about or it is normal engine operation sound.

Here are some additional details for you to diagnose better:
1. There is no tick on cold start and within next 7-10 mins after start.
2. I can hear the ticking noise only on warm engine (mainly after 20 min drive). After ticking noise started on warm engine it doesn't go away unless you park the car for 5-6 hours.
3. I can hear it mainly from the front left wheel area and even more clear I can hear it from the bottom of the engine (under the driver's door)
4. The ticking noise doesn't sound like a loud knocking (like in the videos when lifter failed). It sounds much lighter than that, but at the same time it sounds much louder than injector noise.
5. The ticking noise appears mainly when idling. When you slightly press and hold the gas it disappears. But when you rev it further, it is still there but the volume of ticking noise is getting lower and it gets completely not recognisable at RPM>2000.


The potential scenarios in my mind:
1. Lifter issue (the worst)
2. High Pressure Fuel Pump issue
3. Normal lifter operation sound?
4. Normal HPFP operation sound?
4. Anything else?

Here is the recording of the ticking sound on hot engine (after 40 min drive).
Here is the recording of the cold engine sound (I don't hear any ticking noise)

Please share you thought, appreciate your support.

Shouldn't the dealer be trying to figure this out? Or, is there attitude that a ticking noise is a non-warranty issue because your vehicle still "goes"?

 

[lasallen]

I brought my at4 in for the same tick, dealer said injectors