Random Horrible Noise at Start Up

[topjimmyk]

I just purchased my first Silverado, 2015 LT 1500, 5.3 with 135k miles in great shape after a deer took out my beloved 1998 Tahoe (RIP).

 

Of course it started not to long after I took her home. I replaced all three belts and the tensioner. With a gates kit off rock auto. I spun each pulley by hand and they all felt smooth.

 

I happens after I start it up with or with out the remote start. I get a horrible noise a couple seconds after it starts up. Attached is a video.

 

Any ideas of what it could be?

 

Attached is a Video 

 

[rlcole321]

Did you try starting it up with no belts installed?, try it, then you'll know it's not from the belts, but to me, it sounds like a timing chain or valve train noise. also listen to the vacuum pump closely.

[Bobaloo22]

I had a recall for the vacuum pump on my 2015, might want to check that out.

[topjimmyk]

I don't know if I have a vacuum pump. My next step is to try starting it up with out the belts on. 

 

Edit, I do have a vacuum pump. I'll look into that recall. 

Edited March 25, 2025 by topjimmyk

[JimCost2014]

On 3/25/2025 at 9:46 AM, topjimmyk said:

I don't know if I have a vacuum pump. My next step is to try starting it up with out the belts on. 

 

Edit, I do have a vacuum pump. I'll look into that recall. 

Any play in the water pump pulley?