06 silverado noise

[webulone]

Hi all, First post and I'm hoping somebody has heard this noise before. This is a 4.8 and will make this noise at all speeds and.. WITH THE BELTS OFF. I know it sounds like a pulley. I ran across this video on line and the noise is my truck to a tee. this noise has been scoped by mechanics (non dealer mech.) and I'v got answers from valve train to something in bell housing. Any help would be appreciated. Thanks

https://www.youtube.com/watch?v=gvGMMbcCAK4

 

[zora]

how many miles on the engine?
how frequently do you change the oil?
did any of the mechanics use a scope to look inside the valve covers to see how clean things look?

 

[webulone]

Bought this in 2010 with 46k now has 111k. When bought I changed trans oil and switched to Castrol Synthetic in engine. Oil pressure is normal. Have been going 10k between oil changes. Valve covers have not been taken off yet. I looked at every noise video I can fine and it really doesn't sound like lifers or cam.

 

[zora]

the noise in the video sounds belt related but you state you have the noise with no belt. A recording of your vehicle would be helpful but you already had hands on mechanics check it without clarity. The mechanics who have checked it, are they ASE certified mechanics? If not find one or go to a dealer who has one. Below is one of many links i found on "GM 4.6 engine noise". Some say running some automatic transmission fluid in the oil to break up sludge in the lifters helps followed by an oil change.
http://www.silveradosierra.com/vortec-4-8l-v8/motor-knock-4-8l-please-help-t6121.html

 

[webulone]

Thanks for the link Zora his noise is pretty much the same as mine, to bad he left in middle of tread without saying what the end results were. The video I posted while not my truck the noise is the exact same noise as is the video in your link. I've ran a can of sea foam threw it with no change. This noise just came out of no where about 2 weeks ago. these video are 1 and half yrs & 4 years old and sound different than any cam and lifter videos I've seen. Just wish that poster's would follow threw with what it was.

 

[zora]

you may have to just give in to taking it to a dealer who may have seen enough of them to know exactly what the issue is.