Re: 2011 Laredo V-6 towing issue
You'll likely get more specific responses if you post this in the WK2 (2011+) section rather than the WK (2005-2010) section.
In general, towing up steep grades in hot weather will cause over-heating issues, especially if you do not adapt your driving style to account for it (slow down). If you are trying to climb mountains towing weight approaching the maximum weight of your vehicle at interstate speeds in 90+ degree weather, overheating is a possibility.
Also, does the 3,800 that the trailer weighs include contents? If that is the weight of the trailer itself, when you start adding up all the stuff that you put in it, it will be even closer to the maximum tow rating of your V6.