Strange noise at cold idle and at low torque throttle

The past month or so I've noticed an extra noise I'm my 07 dclb auto (4.0). It is very noticeable when the engine is still cold (I live in canada, this happens a lot). As the engine warms up (and presumably runs smoother) it goes away at idle but can be heard for a moment as I load and unload the power (maintaining 60km/h to idle and vice versa). Once it reaches proper operating temp it goes away. The colder the start, the worse it is.

It emanates from the right hand side of the engine bay (I am pretty sure), and it is not suspension related.

I haven't checked accessory belt but I don't think that's it, that wouldn't depend on ambient temp so much I think.

It almost sounds like a rattle, but is really hard to describe. I'll try to get a video with the noise.

The only thing I can think of that makes sense is that and engine mount has given up. Beyond that, I'm at a loss.

Any ideas? Suggestions? All help is appreciated!

 

Check the heat shields over the catalytic converter and exhaust it might be loose when cold- I had the same problem with my '06 2.7L 2dr Tacoma. I only had to tighten the sheet metal screw and the problem went away. Ron

 

Check where the air intake goes into the fender, I had the same kinda noise and found that the gasket around the air horn going into the fender was bad, allowing it to rattle against the fender until the truck warmed up.