snakeyez

Attached is a photo that I've borrowed from another post on the forum. I have circled with blue the line that my Cherokee runs at normal running. It runs exactly at the thinner white line between the 100 degree line and the 210 line. Is this around 180 or lower?

It runs great. Should I be concerned? Isn't it running cooler than it should? I have no idea what degree thermostat is in there. Previous owner replaced radiator, so I don't know what else could have been done to the cooling system.

fishtaconc

You should buy a point-n-shoot thermometer, to verify the gauge is correct, the sender for the gauge could be covered with gunk, or more likely the sender is not working correctly.

xjsnake

That's a little low. Should run around 200-210 with a 195 thermostat in it.

1991cherokee

If it runs good I wouldnt worry to much about it man... only reasons I could say that it might not be reading the " correct " temp is that the gauge sensor is not giving a high enuff ohm signal due to any reason really... the sensor works off resistance and as the temp rises the resistance rises and gives you a reading. I have delt with this exact problem with a truck I have... nothing to worry about just check the temp sender some day when you have time and if its crusty and cruddy just change it and see what it reads after that...

djb383

Mathematically, it's 155F.

snakeyez

Is it possible it has a 160 degree thermostat in it?

If not the thermostat, then you're saying the engine coolant temperature sensor could be bad?

Heat works just fine. Engine runs good, even at near freezing mornings at startup.

xjsnake

Have good heat? If so it's probably a bad temp sending unit.

99 Purple XJ

Buy a 195 there 5 dollars and easy to change

djb383

Then check electrical connections/grounds at the gauge sending unit drivers side rear of head and at the dash gauge.

snakeyez

Guys, thanks for your help. I just THOUGHT the heat worked fine. Today was the first cold day since I got the Jeep 4 days ago. I had to run the heat full blast all morning and it never did blow hot air, just warm air.

So, tomorow I'm picking up a 195 thermostat and doing a swap. I'll post back with the results. I'm betting the previous owner put a 160 in there.

djb383

........or it doesn't have one.

SilverHaze

or its stuck open.

snakeyez

Picked up a NAPA 195 degree thermostat stamped as made by Stant in the USA. My Cherokee had a 180 degree thermostat in it stamped "MotoRad" (see attached image). I have never heard of that brand.

After installation, the thermostat opened when it should and now everything is perfect. Thank you so much!

jakbob

you should see an increase in MPGs as well. i had the same problem in my renix, put a 195 in, and blamo... 16 mpg and thats with a day of wheeling (as opposed to the 9 i was getting before)

xjsnake

Good to hear we could help and that it was a simple fix.

Stay warm!