Guys:

I have a front end noise that is bothering me. It sounds like a buzzing, a high-pitched rattling. It almost exclusively happens under load at low rpms and it dissapears at moderate to high rpms. Curiously, it also happens when I start the truck up, right as the high idle is ending.

Other info: the problem is less evident when the engine is warmed up and running smoothly. The pitch/frequency of the noise does not vary with rpm. The truck idles wonderfully. Exhaust components and heat shield are tight.

Any ideas? I am paranoid about the timing chain (100K miles on the girl).

thanks

scott

 

Check the belt(s)...Could be slipping maybe.

 

I'll check them again. Checked them 5K ago and they were OK. The serpentine belt was replaced 15K ago.

Any other ideas? This thing has stumped me. Loose/damaged engine mounts were another idea I had, how could I check for those?

 

what engine you got in there?

I don't realy know how to check the engine mounts...I didn't know my sisters need to be replaced until the other day she came home and her engine was 2 inches off the ground LOL glad it wasn't my truck.

I'd try maybe laying under the truck while someone revs the engine and see how much movement there is with the engine.

 

SPROCKET_X:

I have a 302. Good idea about peeking from underneath. I stood in front of the engine and revved it by pulling the TB lever, and didn't notice excess movement. Mind you, the engine moves a fair amount under WOT in neutral, just didn't seem excessive.

Also, the noise doesn't occur in neutral.

Thanks for the input, guys.

-Scott