Rattle Under Light Acceleration

I have a 2007 DC, 2WD, 4.7L Tundra with 108k miles. I've only only it about a year, and really haven't done anything major to it. Oil changes, brakes, diff fluid change.

Under light acceleration, like when pulling away from a stop sign. I get a high pitched rattle, like a spinning bearing in a metal can from the engine compartment. If I go from light acceleration to heavy acceleration the noise goes away. I only hear it when pulling from a stop, or if I'm driving slowly up a hill, so light torque situations. It's starting to really bother me.

I have a hard time replicating the noise when stopped, in park or Neutral, which makes finding the source pretty tough.

My first instinct was idler or tensioner pulley, but I figure that noise would be more constant and vary in pitch with RPM. I removed the surpentine belt and checked the pulleys. Nothing sounded like the typical dry / failed bearing sound. None of the exhaust heat shields feel loose.

I haven't had a chance to put the truck up on my 2 Post Lift to try to replicate the noise in Gear that way. I'm in the middle of a TR6 restorations and the frame is on the lift, and not quite ready to put the wheels on yet so difficult to move. I'm still a few weeks from being able to put some wheels on the frame and pulling it out to free up the lift.

Any thoughts on things to check?

Thanks!

 

Did you resolve this? I have something similar going on ....