1994 SL2, Cold Rattle/Warm No Rattle Slight Hesitation

[acidburn_335]

Hey Guys,
I own a 1994 SL-2 1.9L DOHC w/ 136K auto-tranny replaced at 127K. The past week I noticed that I get a rattle coming from the lower belts/lower exhaust region when the car is cold. Once the car warms up rattle is almost non-existent unless you are really listening. The rattle sounds like a metal tinpan. I do not recieve a SES light nor any other dash lights. I have checked all lines in the surrounding area and all appear to be tightly secured. I have checked the fluids which seem to be their proper colors and levels. Checked valves/lifters which are also getting oil to them so the problem isnt there. Ive also checked the upper engine mount which also seems to be ok as well. The car has a solid idle, and no problems shifting gears. Ive only noticed a slight hesitation which is somewhat random. I do not recieve engine shakes from a mount gone south.

I have noticed that the lower pulley does have a slight shimmy to it. Is this normal for the lower pulley?

I assume that both hesitation and the rattle are the same thing. If not then I would attribute the hesitation to leaky valve cover but the rattle to something else.

So my questions Doc are whats the prognosis, the cost and easy to do myself (and if taken to a mech how much?).

Thanks,
Tim