Oooh please dont mention Jeeps to me, they're a pain in the neck everytime they come out offroad with me. the old Cherokees and Wranglers had (still have) an overheating problem, most guys I know changed the radiators to custom made ones.
As for the new Jeep Liberty, they have transmission overheat problems. so everytime we're offroading, we have to stop and wait for the Jeep guys (Liberties and OEM radiator ones) to cool off before we can continue.
Bear in mind this is extreme hot weather conditions, 125 degrees F. + dry and sand dust. As an example, after EACH outing I have to clean my K&N on the Blazer.
Surprisingly, Nissans and Toyotas that tag along dont have that problem, out of American vehicles, only the Tahoe/Yukons and H2s dont overheat and now the H3, but most other American trucks tend to overheat.
As for my Blazer ZR2 (aka BlaZeR2) I did a focused modification on the entire cooling system to make it run right.
And ....f5fstop...the nickname is SledgeHUMMER not SledgeHammer
SledgeHummer