Rattle on Cold Startup

[PunchT37]

Is this just a characteristic of these things? 2025, 1500, 5.3, 10 speed. Been like this since new. Not that cold down here in south Louisiana but, the colder, the worse. Fast, short rattle. Followed by clicking under the truck. After a few miles, quiet as a mouse. If it`s not too cold out, the clicking is still there till warm even though the rattle is not there. Got 2100 miles now.

 

It really does not sound like the engine. Anyone else notice this? Truck runs fine otherwise.

[Bikerjon]

On 1/6/2025 at 11:52 AM, PunchT37 said:

Is this just a characteristic of these things? 2025, 1500, 5.3, 10 speed. Been like this since new. Not that cold down here in south Louisiana but, the colder, the worse. Fast, short rattle. Followed by clicking under the truck. After a few miles, quiet as a mouse. If it`s not too cold out, the clicking is still there till warm even though the rattle is not there. Got 2100 miles now.

 

It really does not sound like the engine. Anyone else notice this? Truck runs fine otherwise.

I have not noticed this on my last 2 5.3L  10 speeds. (2021 and 2023 Trail Bosses.) There have been postings on this forum about clicking noise coming from the high pressure fuel pump, that is a normal condition. Could the lifters be bleeding down and rattling untill they pump up? You may want to leave this at your dealer overnight and have them diagnose in the morning on a cold start.

[dieselfan1]

Chevys  have been rattling like that for years on cold start.

It's normal.  I've owned 7 new Chevys since 2007 . They all did it  My 22 5 3 does it as does my 23 6.2.

The ticking is the fuel pump. Also normal. 

[diyer2]

My 93 and my 2012 don't rattle. 

[PunchT37]

I could swear it`s the trans pump gears. It`s gotta be a cold start while cold outside. Not just a cold start while warm outside.