Yeah I'd flush that puppy ASAP. If it's got clogged fins I'd replace the radiator.
I would also switch over to the green coolant found everywhere in the USA vs the Jeep/Chrysler HOAT which is very hard to find except at a dealership. Everyone on here swears the green coolant is bad for your engine, but it now last up to 100-150K and with a full coolant flush you shouldn't have any problems. My 05 with less than 20k on it had nasty crude in the overflow reservoir and it was nasty when I flushed it (I bought my 05 with less than 3k on it and I never added any coolant). I went to every auto parts store Auto Zone, Advanced, and Oreilly's and not a one of them carried HOAT and would have to special order it.
I now have 52k on my Jeep and the coolant is very clean with no "sludge" in the overflow reservoir!
05 Electric Lime Green LJ with a 4spd Auto, 2.5inch Suspension Lift, OME Shocks, OME Steering Stabilizer, 32inch BFG M/T's on 17inch Moab's using Spidertrax Spacers, UCF Aluminum TC Skid, Novak Cable Shifter, Brown Dog MML, Rokmen 1/2 BL, Banks CAI, Diehard Platinum Marine Battery, JW Speaker 8700 LED Head Lights, Safari Nets, G.E.A.R Overhead Console/G.E.A.R Tailgate Storage, Rugged Ridge XHD Front Bumper, Warn Gas Tank Skid, Mopar Rock Crawler Rear Bumper, Warn XD9000i Winch with Warn Wireless Remote, and a Uniden 880 CB Radio