Rattle while accelerating, only when engine is warm

OK, here's the scoop-
I have a recently purchased 1995 4X4 Tacoma with the 2.7 liter, automatic transmission, and 79,000 miles on the odometer. I am hearing, for lack of a better term, a rattling noise when accelerating, but only when the engine is warm. The noise does not occur when the engine is cold, even at sub-zero temps. The noise does not occur in park. I am running 89 octane, and just replaced the oil with Mobil 1 full synthetic 5w30. Any insight into this issue or advice on diagnostics would be much appreciated.

 

Does the rattling get louder under high rpms or higher speeds? Can you feel it through steering wheel or just in general? Have you tried revving the engine outside the vehicle from under the hood to try to replicate said rattle? Does it sound like it's coming from the front, inside, rear? Need some more info

 

Thanks for the response-
The noise does not get louder under high rpms., and I can't feel anything through the steering, accelerator, floor boards, etc. Everything is smooth.. Manual revving from under the hood does not produce the sound. The noise seems to come from the lower driver's side of the engine compartment.

 

I'd suggest starting simple, jack up the driver's side and man handle the tire to see if there is excessive play in the suspension. I know it doesn't really play into the whole warming up thing but it could just be coincidence.

 

Catalytic converter on that side?

Exhaust heat shield loose?