just last week I finished putting a new engine in my 1991 jeep Cherokee. The new engine has 130,000 miles on it, was rebuilt by mopar in '97 and had the head redone before I put it on the block. Everything runs very smooth and very quiet. I bled the cooling system, put new thermostat and new water pump(not in that order). Radiator was probably put on about 15,000 miles before the engine swap. Electric fan turns on fine. Mechanical fan seems to work ok. Water hoses are not collapsing under higher rpms. The question is why is my temp getting up above 210. I know these thing run hot but I want to keep it at or under 210 at all times. My plan is to lift and crawl this jeep but need it working to my standards before I take it on the trail. Anything helps.

Thanks

 

Mine gets to 230 when in the sand.

I'd make sure you're using an OEM thermostat and not an aftermarket one, aftermarket ones are junk.

 

Have you verified temps with an IR gun?

If not I wouldn't rely on the dummy gauge. It only gives you a ballpark. Verify and know.

 

x2 on this.

Perfect example, mine is showing almost to the red all the time. But it's at 200-210. When the Aux fan kicks on, I know it's starting to get a little warm. But only a little.

 

yeh, infrared thermometer gun .. my guage tells me its +20F degrees over of what the actual temperature is, you can get one for around 25$

 

Like everyone else says, verify with IR gun.

As for the Mopar thermostat, I am not so crazy about the one I just installed last week. It cost me around $30 and my temp fluctuates more now than with my 3 year old Gates thermostat. Just put in a quality thermostat.

 

Yeah, I prefer the Stant 195* thermostat. Seems to keep the temps consistent.

 

this one base?

I remember last time I looked I saw a few different ones but now I'm only seeing this one so it must be it.

 

i just took "the plunge",had some reward points cost with shipping apx $5!!.
amazon

 

Yup, that's it. Inexpensive and effective.


Click for full res

And made in MURIKA!

 

Thanks guys. I already have an ir gun. I'll check it later today. The next step is to get rid of the super thin aluminum/plastic radiator and go with the 3 row csf radiator.

 

stock replacement from AutoZone is perfectly fine and does a good job. aluminum radiators are hit or miss it seems.

 

x45 on checking actual temps. The 4.0's operate at 205-210. so seeing 212-215 is not uncommon. I would see 220 on a completely refreshed system climbing uphill, AC on, doing 75mph on a 90 degree day. No need for a 3 row radiator, CSF's are known to crack after a couple years. Make sure your stock system is up to par. Have you flushed your tranny fluid recently? the Heat exchanger for the aw4 in the radiator can bump your temps up a tad, if the tranny is getting hot.

 

Thats what I have in mine and it has worked perfect fine so far! I have had my Jeep out in the dunes and even after cruising around for 60+ min in 4 low going slow, I never saw the temp go over 220°. I have a dirt cheap $50 Fleabay radiator in it too.
X46 on checking actual temps with IR gun

 

just for clarification. You have a stock replacement or aluminum radiator...haha I apologize I just am slightly confused