2024 5.3 Ticking

[blanchard7684]

It has pauses as you mention. It isn't a steady rhythm. like tic tic tic tic_____tic___tic____tic tic_______tic tic tic tic_____tic____________________________tic___________tic tic tic_________tic repeat

its 17/32 time not 4/4 lol.

I stehoscoped the high pressure fuel pump. Although that thing is loud and noisy, shockingly so with stehoscope on, the noise is not in same rhythm or quality. And it is constant.

This only occurs in first 5 minutes or so.

I heard most noise in catalytic converter on passenger side. I've heard same sound from driver side as well. The collecter where the cross over connects with driver side exhaust had noise. The heat shield had noise. And I could barely hear it at the exhaust manifold flange. I had nothing on the manifold itself or near the spark plug.

(nothing on the valve cover, timing cover, water pump, oil pan, block, transmission pan, transmission housing, even checked the front shocks, and the brake HCU, and refrigerant a/c collector.)

So the noise got worse as I went toward the catalytic converter, got loudest at the catalytic converter, and subsided downstream of the collecter.

It isn't the exhaust flapper/damper either. That was the first exhaust component I checked.

 

[viven44]

Sounds like exhaust system components expanding/contracting. Usually more obvious on cooldown when engine isn’t running. Usually sounds like something is dripping or ticking.

 

[Khantahoe89]

How fast is the ticking sound?

Is the noise a faster Tic, Tic, Tic with a constant timing or if the noise a Tic with pauses like Tic _____ Tic _____Tic _____Tic?

A slower Tic tends to be sometimes warm up expansion of something. Faster, rhythmic ticking usually is tied to something rotating or operating with the engine RPM.

I do know there have been complaints of the High Pressure Fuel Pump and high pressure fuel system components making ticking noise. This is why a lot of newer engines have insulated covers on top of the engines to try and mask some of the mechanical sounds from the engine or fuel system components.

Pull up to a wall on the drivers side with your window down and this usually reflects the noise back so you can hear it easier. A drive thru tends to be a good way to hear what may be going on with the car if no other noises are drowning out your vehicle.

I have a same noise on my 2024 tahoe 5.3 and made an appointment for next week. Just concerned and hoping its not something big.
Here is a link to the sound i posted to youtube. Any feedback would be highly appreciated.

 

[jfoj]

First listen and first question.

A number of noises happening, are you referring to what I would call the "Snap" noise that is somewhat random? Maybe heard it 15-20 times in the video randomly.

Just trying to make sure I focus on the correct noise.

 

[blanchard7684]

First listen and first question.

A number of noises happening, are you referring to what I would call the "Snap" noise that is somewhat random? Maybe heard it 15-20 times in the video randomly.

Just trying to make sure I focus on the correct noise.

Yep

 

[jfoj]

Understand I am listening to a recording and this is just my FIRST thought. To me it almost sounds like a spark discharge noise from maybe a bad coil or plug wire.

But this is just my FIRST thought. Maybe it does have that "SNAP" sound like an ignition discharge noise but is something totally different.

 

[blanchard7684]

My stethoscope says it is the catalytic converters... same time rhythm

 

[jfoj]

I assume these are monolith/honeycomb converters?

Maybe the catalyst is expanding, but this is scary if snapping unless something is firing off in the converter. If expanding and making the snapping noise, I wonder how long before the rattles start?

 

[blanchard7684]

Hmmm never thought about something cooking off...

 

[RG23RST]

I wouldn't say they all make that snapping/tick noise, but the majority do. It's been a thing for years now. The fleet trucks I see with the 5.3 do it although I have noticed less of it in units over about 40K miles. The retail stuff is the same way. No clue what it is.

The catalyst brick on these engines makes some "interesting" noises. Once everything gets good and broken in they can almost make a "hoot owl" type noise tapping the throttle in park. Per GM it's spark retard because we do get concerns about it.