Hi community,
My 2022 Tahoe 6.2 engine ticking.
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 (see cold start recording)
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. (see warm engine tick video)
3. I can hear a tick 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). There is a minimum noise on top of the engine.
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 louder than injector noise.
5. When I am revving the engine the noise frequency increases but the volume is not much increasing (see the revving tick video sound)
Please help me with the root cause of that. Should I be worried or this is a normal sound?
See attached videos. The sound in a video is a bit louder than in reality due to sensitivity of the phone microphone.
Sound when engine is cold (no tick as per my understanding).
Warm engine ticking sound:
Sound of ticking when I put a phone under the car and rev the engine:
Thank you all in advance.
The belt theory varies by situation. Felt noises can sometimes get worse based off of temperature. For a prime example many times a vehicle will squeak a belt while it's cold and then as it warms up this week goes away. It can do the inverse but it's less common. Same goes for the rock. This is because of materials expanding and contracting at different rates. A rock will expand and contract at a different rate than rubber or metal for example.
As for the cam lobe theory you brought up about the speed of the tick. Technically the camshaft spends at half the speed of the crankshaft. Your RPM is based off the crankshaft. This means that the tick that comes from the three lobes for the fuel pump will only be 33% faster than engine RPM. That tick that you have has the sound of a high pressure fuel pump tick but I think it is maybe going a bit too slow for the high pressure fuel pump. It's hard to say though because it's close to the correct speed depending on what RPM you are exactly. You could also have a lifter with a small pit in it that only text when it's hot like I have in one of my videos. But to me that tick that you have seems a bit too fast for that unless the pit is on the roller of the lifter and since the roller of the lifter rotates twice as fast as the camshaft approximately then it could be that. Perhaps the roller of the lifter has a small flat spot in it that only shows once the oil thins out because it's nice and hot.
In the revving video the regular noise seems to overwhelm the ticking sound. So you can't really hear that the frequency of the sound increases with engine rev. Regardless though, have you tried letting it warm up then pulling the belt off and running it just for a couple seconds to see if the ticking is still there with the belt off? It's possible you have a small rock in the belt and only when it hits a certain pulley does it make the clicking sound. Other than that it almost sounds like a high pressure fuel pump tick when you take the little sound deadening pad off of the fuel pump. I wish the other noise of the engine wasn't so loud versus the ticking sound so I could hear it a little better. It is such a new truck though that you could probably go to the dealer and take a test drive of the same basic truck. Then while on the test drive once it's warm see how much different it sounds from yours. Be kind of a pain in the ass to go that route but it is an option. Is this vehicle still under full warranty?