canada_man

I have a 1990 jeep cherokee with the 4.0 that is not getting up to temp. I have verified with a temp gun and got all sorts of readings depending where on the head I was pointing. At the thermostat the highest I saw was 177f. The gauge fluctuates between 80-90*C (176-194*f).

Replaced thermostat a few months ago when I did the water pump and fan clutch. Used a 195* Stant. I replaced the Stant this wknd with a napa oem equivalent 195*. Boiled both while they were removed, the Stant seemed to begin opening at 190 and the napa one at 195.

I have a cts coming to replace mine with an open circuit. Could this be causing my problem?
I am constantly tightening gear clamps as they seem to always leak (new hoses and clamps). Also have a minor heater core leak (no inside frost or smell). I'd say in a 5000km oci I add 1L of coolant (I believe mostly from evaporation as I never see coolant on the ground).

When I burp the system I let it warm up with cap off, shut off and cool, add coolant, cap on, go for a drive, come back and let it cool then add more coolant. I've done this on an incline as well to put the thermostat higher. Still running the closed system.

Could a coolant passage in the engine be clogged causing this? I have good circulation through the heater core and decent heat from the vents (warm enough for -20*c but not -30. Also I have a small vac leak that I have been unable to locate (thinking it's in the dash) and wondering if that could be the solution or part of (when I accelerate moderately/quickly the blower cuts out).

Any help is much appreciated as I realize this is a very busy time for most.

canada_man

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toasterknight

If the ambient temperature is -20 I'm not suprised your having issues with operating temp. Will it get to temp sitting?

Firestorm500

Remember that is Centigrade/Celsius scale for him. But it is still -4 degrees Fahrenheit.

His gauge sits higher than the one that was in my '87 Renix. It actually looks about right, especially based on his ambient temperature.

I ended up eliminating the heater water control valve. The cabin warmed up quicker and was warmer overall.

He might try putting cardboard in front of the radiator to cut down on evaporative cooling.

OP, your vacuum leak is probably under the hood somewhere. The inside tubes are well protected from the elements. The tiniest leak can cause what you are experiencing. The blower fan itself is not cutting out. The internal blend doors are losing vacuum. They go to Defrost, which is the default setting.

canada_man

It will not reach proper temps even sitting idling. Those pictures were taken after about 15-20 min of idling in a heated garage, although the garage door was open. I use a spray bottle full of water which makes a good mist for find the vacuum leaks.

cruiser54

As for the "blower cuts out" I would suspect a vacuum issue.

Firestorm500

Block off the radiator. You're getting too much conductive cooling into the atmosphere.

You can estimate that 1/3 of engine heat is removed by the cooling system (and oil), 1/3 is removed by exhaust, and 1/3 is lost to the atmosphere due to radiational/conductive cooling.

Neither of my XJ Cherokees had very effective cabin heat with temperatures at 15 degrees F or lower, and speeds above 40 MPH. I eventually put Mopar 195 degree thermostats in both. The Mopar thermostat allowed for quicker warm-ups and more stable operating temperatures under standard conditions.

cruiser54

At 20*F I can run any of my Jeeps for 5 minutes or 5 miles and be at operating temp using the factory thermostat. The Napa and Stant didn't do that.

andysmithJEEP 2000 XJ

Do you know where you can get a factory thermostat? My jeep is not getting above 180 degrees. That's reading the CTS from the REM. I have a 195 Stant.

robsjeep

If hose clamps gone loose, make sure you are not using the type with perforated band. rubber hose material gets slowly squeezed thru these perforated holes, which in turn loosens the clamps. Use a clamp without holes in the band.

good luck

Flynn

Looking at your dash pic, temp. gauge looks normal to me. I have a 90' RENIX as well that is my DD. I do block off the radiator with plastic panels that plug into the grill. When-ever I do a quick glance at the dash, I expect the needles to be at 12 o'clock. If elsewhere, I start to pay more attention to the gauge. Your battery gauge looks low to me. Nothing to do with temp. but just an observation. Lucky you, I wish I could afford a full tank of gas.

EuroJeep

My 87 is also slightly to the left of 12 o’clock.
this after calibrating the gauge with an infrared gun pointing at the hottest point of the water pump.
So yours seems pretty ok.

Yes, battery gauge looks too low.