I recently purchased this vehicle with about 45,000 miles on it. There are 2 annoying issues
1) high idle 1500 rpm on cold startup and takes 2-3 min to get to 600rpm.
2) At any driving speed above 12 mph when I release the throttle, the car does not react and maintains speed as if it was on cruise control. It will gradually slow down (from 60mph it takes 70 seconds to get to 30mph) .
When I use the brakes I can feel them fighting the Hemi and all the weight of the vehicle and when it gets down to 800 rpm, i can feel the throttle release and the rpm's drop to 500.
The vehicle is still on warranty but the dealer will not do diagnostics since there are no error codes.
Any ideas?
One more question, do the rpm's drop as soon as you release the gas pedal (for instance at 60 mph ie. 2000 rpm) what happens on your Aspen?
Thanks in advance for any replies. Warranty expires in 10 days.

 

A few more details: the 70 seconds example I gave from 60 mph takes only 35 seconds when I put the car in neutral and let it coast.
The rpm's drop instantly when I blip the throttle in neutral, so not a sticky electric pedal.

 

I have an 08 with the Hemi also. I hate the cold high RPM's also. I have had it two months and does it everyday. I also had a Volvo that did this but the higher RPM's only last 15-20 seconds. My Hemi's last a couple minutes at higher RPM's.

 

I'm not sure if this is what your experiencing but after a quick review of TSB's for the 2008 Aspen with a 5.7L HEMI there is a software update available via TSB #18-006-10 Rev. C that enhances the MDS (Multi-Displacement System). If you think this is the issue your experiencing, you may want to review this your dealer as this issue does not trigger a fault code.

Below is a description for your review:

SYMPTOM/CONDITION:
The customers may experience that the vehicle has a harsh engagement or has a
buck/jerking feeling at low speeds of around 12 mph to 15 mph. The customer may also experience a harsh engagement or buck/jerking feeling during highway cruise control operation from 65 mph to 75 mph. These conditions are caused by excessive MDS transitions.
The MDS low speed engagement point has been changed to 21 mph (34 kmh). In addition to the MDS low speed engagement change, enhancements from V8 to V4 and V4 to V8 in all ambient temperatures and operating ranges have been made to make all the transition less noticeable to the customer.

 

My 09 has high idle at first. I think that condition is normal. It's especially noticeable after sitting a few days w/o being driven.

 

Mine must have the software upgrade because my MDS kicks in at 21 mph after the car warms up. I has to be driven or warm up for 5-10 minutes before the MDS works.

 

My '07 5.7 bucks at low speed. It takes me about 3-4 minutes to get out of my neighborhood at 15-20 mph, and I just live with it. Not desirable but livable. But as ChryslerCares said, have the Stealership check the TSB.

 

That all sounds normal for this vehicle. I had an 04 Durango that was the same way -- also had the hemi engine. This engine wants to maintain speed and will coast at high speeds for awhile before slowing down. Don't rely on engine braking if you own a hemi!

 

Thanks for all the replies. The software updates were done last week, no change. Some one said "dont rely on engine braking with a hemi" however the coasting time is double what it is compared to coasting in neutral so nevermind no braking, there is engine momentum being created.
My Aspen has a Magnaflow cat-back dual exhaust system(beautiful sound) , could this be causing the problem, perhaps the lack of back pressure is throwing off the sensors? Anyone knowledgable on that topic ?

 

2x on that.