I have a 2008 AWD Aspen Limited with the Hemi. Every morning when I start the car, engine noise is so high, it is a nuisance for the neighbors - it sounds like an engine revving at 5000 rpm or so (it is below 2000, in fact). After driving for about 1 to 2 minutes, it will calm down to normal levels. I live in Georgia and we don't exactly have cold mornings anymore right now, so it is not outside temperature related, just engine temp.
Had the car at the dealer and asked him to check into it and they told me that's normal.
I had a 300C with Hemi before and that car never showed ANY increased noise when the engine was cold.
The effect is the worst while you are still in P position - so especially if you are remote-starting the car, it will just sit their with the engine screaming to high heavens until you get in and get it rolling.
On the good side, this is my biggest complaint after almost a year with my Aspen - not bad. But boy I'd still like to get it fixed somehow - or do you guys experience the same with your Hemis?
Marc

 

It's a little loud at startup, but mine sounds exactly as you describe. I have the same year/model/engine, with the same characteristics. I think it's common for cars to rev a little at startup, but the large engine + fans and exhaust combine for a "truck-like" experience. I personally like the way it sounds.

 

Thanks for the reply - it is so hard to describe such a subjective thing. What's loud to one guy is quiet to the next. Lets just say that not Yukon, Durango, Hummer, etc. that my neighbors drive comes close to it.

 

I am sure Chrysler Tech or someone else can chime in but my 07 Aspen and 06 Durango Hemi's do the same thing. On mine, I believe it is the fan clutch. When cold, the fluid in the clutch is more viscous, causing the fan to engage. After a half minute or so, she warms up and the fan dis-engages. Roars like an airplane at first start up tho. Sounds like a mans truck, I kinda like it too.