Threw my 2 row CSF in last winter so this is the first summer with it. With the old stock one I'd run steady at 200-210 in hot weather.
The noew one and I'm running hotter at a stop, and the aux fan kicked on twice today in traffic. It never turned on with the stock rad till I blew a mount and the mech fan stuck on it's shroud.
shouldn't it runn the same if not a bit cooler with a CSF? Pump's fine as far as I know, and fluid is fine. Stat is new as well as cap, no leaks.

 

the mechanical fan could be taking a crap. (fan clutch)

 

Less than a year old.

 

New rad may not be as efficient as original rad. Two 5/8" wide rows are not as efficient as one 1 1/4" wide row.

 

My Jeeps running warmer lately.. i attribute this to the heat wave we have been having.

Are you overheating?

 

No not overheating but it was only 77 today. It did it idling in traffic, and after highway driving.
On a related note, when my block bracket blew out and my engine sat to thw side, my mech fan was unable to rotate for at least a couple hours on thew trail and getting her home. Could all that spinning have ruined the clutch?

 

yes it could have ruined the clutch.

 

I recently replaced my leaking 2 row rad with a 3 row aftermarket rad. Since I live in the desert, cooling is pretty important, and the 3 row rad made a difference, especially when running the A/C.
Might try replacing the rad cap; although rare, even new ones could be defective. If it's not holding the pressure, it can cause overheating. I'm assuming your tstat is OK, but just FYI, I just discovered a little gem at AutoZone-a tstat that locks in the OPEN position if it malfunctions.

 

Wonder at what temp they lock open?

 

i had issues with my xj running warm. i found drilling a small hole(1/8" or smaller) or two in the t-stat help tremendously with keeping the engine at 195*. also, did you replace the fan shroud? they are very important to help keep airflow through the radiator and not just swirling around the fan. i would replace the fan clutch anyway because of what you did to it. cheap insurance anyway. get the heavy duty one for the ZJ, NAPA part number 272310.

zedpapa