I just did a thorough coolant flush on my 99 XJ the other day. It was probably the first in awhile as the coolant was pretty nasty. The PO did not have the cooling system maintained very well. Anyhow, I flushed/back-flushed it using a Prestone t-kit and then replaced the water pump and thermostat (NAPA water pump with OEM 195 t-stat from the dealership). Then I separately flushed the block through the WP/thermostat holes, the radiator through the fill neck, and the heater core through both of the hoses. I then filled it with straight distilled, ran it for another 10 minutes with the heat on, and drained it. I put in 6 qts of concentrated Peak green coolant and filled the rest with distilled water. As I expected, it is already starting to turn brown again. Today it was pretty hot here in Washington (around 85) and I noticed in stop and go traffic, the temp noticeably increased. It was almost at the notch above 210. My question is, am I at risk for any damage at this temperature? I'm not sure whether my problem lies within the radiator or the clutch fan. The fan feels pretty good when hot (spins freely about 3/4 of a turn). The radiator is original OEM with around 65k on it. Any input would be greatly appreciated. Thank you.

 

Pretty normal. I'll see 210-220 sitting in traffic on a hot day.
Might try one of the radiator flush products if the antifreeze is getting nasty already.