After some rain and snow I started my 01 Silverado with a 5.3 and heard this. What do you think it is? It fades then comes back at idel.
Hi Nailhead Ronnie.. No expert, but I would check all belts and pulleys, I think it sounds like something dragging og rubbing..
To echo the above post, I've heard idler pullies make some pretty funny sounds at idle, especially if foreign debris was introduced. Not sure that's your issue here, but it's an easy place to start.
Take the serp belt off and then start it. No noise? start with idlers and pulleys. noise still there pull the insp cover off the trans and check back in that area
A.c. compressor bearing makes a terrible noise like that when worn . turn on ac and if it goes away you pin pointed the problem.
smash it with a hamner!!! Ok, I can't add anything here, but those are some great troubleshooting suggestions guy. Once you do something a time or two, it's "common knowledge", but if you have never seen it, it's a bloody break thru. Really appreciate the folks here, unbelievably helpful group. Hope your thanksgiving was great.
Thanksgiving was great. Sorry for the late reply guys I had to work today. I'll do as guys said. And thanks for everyone's help.