I replaced the t-stat with a 180* stat. I also went to the Jeep dealer and got a TJ fan for 2000-2003. Then I went to Kragen and got a heavy duty haynes fan clutch. Temps are always at 177*!! Why?

Well, here is my theory. The t-stat opens sooner, the bigger fan cools the coolant sooner thus keeping the engine cooler Not to mention more air on the motor.

Pictures below say a thousand words. Second picture was taken when it was 105* outside while I was driving around town.

Any questions, just ask.

Ron

You do want more cooling capacity from your system for towing and crawling in low gears but you can also over-cool your engine. Once the engine reaches proper operating temperature the ECU programming will adjust fuel delivery and timing to achieve minimum emissions, better gas mileage and power. If you over-cool the engine your emissions can get stuck in open loop mode never reaching a functional operating temperature. This condition can also cause problems passing smog because in open loop the ECU runs the engine rich for the cold-start cycle. This is a common condition when a stat gets stuck open or someone removes it completely, another condition can keep the stat cycling open/close rather than staying open to allow continued circulation of coolant.
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I agree. On an OBD I I think it is 172*. So, at 177* I am good OBD II is higher. I think it is 177* +/-.

So, pre 1995 which is OBD I, your good. I have ran this set up on all my OBD I. Funny note, the Avalanche I had "2004" and now my Suburban 4x4 "2002" both had 184*. Chevy did away with the 195* stats I guess.