Metal to metal scraping noise

[gonoles12]

Have a 02 Chevy Suburban. Getting a loud metal to metal scraping or grinding noise from engine. This happens while driving at constant speed then slightly applying or decreasing throttle. It lasts only for a couple of seconds. I was able to get same sound in "drive" with brake applied and then applied throttle (adding slight load to engine)
I replaced all belts and pulleys on engine thinking might be the problem. Any thoughts?

[maxwedge]

Usually diagnosing issues like this on the net is less than guesswork, anyway may be a exhaust shield grounding/loose?

[gmtech1]

I agree with Max...tough to tell on this end, but does sound like maybe a exhaust shield.

[gonoles12]

thank you both, I thought of that but the sound is not a vibration nor rattle rather a squeal or high pitch grinding sound??

[Tech II]

Compressor clutch?

[j cAT]

If ths occurs when the vehicle is in motion then it maybe in the drive train. the transfercase when failing makes these type noises.

then theres the drive shaft joints.