temperature question

[rynmccarty]

I have a 92 4.0 and the temperature gauge fluctuates between 195 and 210 while driving. I have replaced the thermostat, radiator, and sending unit to the gauge. Before I replaced the thermostat it would run at 160 consistently with no fluctuation which led me to believe it was stuck open, after the thermostat it starting fluctuating. So I had a shop replace the radiator and it fluctuated between 160 and 210. I changed the sending unit and now I am fluctuating between 195 and 210. Please help it is driving me nuts.

[Vape]

I know I dont have the same engine, but all my guages except the battery wiggle around a bit between notches. Never bothered me, and my vehicle hasnt had any problems yet. Dont get me wrong, jumping from 160 to 210 I'd see as a bigger deal. But (and maybe this is my inexperience talking) I never was bothered when they moved just a little. I dont think theyre meant to be that precise, just to give you an idea, but I could be wrong.

[pete925]

Go to this thread about flushing and sporadic temp gauge reading.

http://www.jeepsunlimited.com/forums/showthread.php?t=882315

195 to 210 is pretty normal temp. for most stock Jeep motors.

As long as there's no pinging and erratic engine idling going on while the motor is running, then i think you're ok.:hoos:

[Alabamaranger]

Sounds normal, I run a flex fan and it helps 100% at slow speeds.

I have a 180 in my 4.2 and when offroading at craw speeds and under a load, I have seen the gauge go up to 210 but cools back down as soon as the load is off. With the Flex Fan, it stays around 180 all the time. You can tell the fan sucks a lot more air in verses the stock clutch fan. I just have to stay out of deep water - I hate to see what would happen if it hits water real hard.

Some would argue that a electric fan is better but you have a large current draw when you are moving slow and if you have all your lights on at night. That alt has to work really really hard to keep up.

[Nightwing]

The stat number (160 etc) is the average temp when it BEGINS to open....so fully open on good system usually reads 10-15 degrees higher.

My 4.2 runs a 160 (I live in hot climates, w/ A/C!)...& typically runs @ 170, rock solid. Did you put a new cap on that radiator?

The pressure cap is really important to the cooling system. Not only does it pressurize the system, raising the boiling point....but it also allows for vacuum from the cooling radiator to such back in the fluid it has displaced to the overflow tank. Without a full overflow tank & leak free hose connecting the two your cooling system will constantly be low.

It makes a 20 degree diffference in my 4.2 between a few cups low & a full radiator. Before I replaced my cap it ran @ 190 & I had to top it off all the time.