Rattle Noise/ Bearing Noise Help

[EMS_0525]

Hi everyone this is my first post, I have a 2000 GMC sierra ext cab short bed with a 4.8L, and its 4wd. There is a rattle noise or something when i accelerate, it almost sounds like a bearing on the serp belt system, but i have use a stethascope and havent found it. My buddy says its just the motor pinging... i dont think it is.. The truck has 120,000 miles on it, i know its gonna have some noises with the mileage, but its really annoying and i dont want something to break on it. The noise is coming from under the hood, and its throttle related, or vibration related, doesnt do it at idle, but i can hear it while i drive.... anyone have anything like this or know what it could be? I know this is a shot in the dark but thaught maybe someone could help.... Thanks in advance

[Draenor]

A rattle and a failing bearing will be two distinct noises. If its a rattle it could be an exhaust shield that got loose.

 

If it sounds like pinging, try running some seafoam to clean out the accumulated carbon.

[Zembonez]

A rattle and a failing bearing will be two distinct noises. If its a rattle it could be an exhaust shield that got loose.

 

If it sounds like pinging, try running some seafoam to clean out the accumulated carbon.

Yeah... I agree with John. If you have 120K on the clock, there might be a real carbon buildup. Even if it isn't the noise it would be excellent preventative maintenance.

[EMS_0525]

Yea im going to get a can of seafoam here real soon... on that.... just use the brake booster to get it in? I have to snoop around under there to see if i can identify where its coming from...