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Should I be able to see coolant moving?

4K views 52 replies 13 participants last post by  Gigemags05 
#1 ·
I noticed recently, that my temp gauge is creeping closer to the H than it ever has. That being said, this is probably the warmest weather I have driven it in since getting it on the road. Still feeling uncomfortable with the gauge reading I decided to change the thermostat. Ran it without radiator cap to burp it and did not see any "flow" when looking in the radiator. Temp gauge went really close to the H again so I decided to shut it off. Should I be seeing movement of the coolant?
 
#38 ·
Ok. I just checked it again with the meter switched to 200 instead of 200k. Cranked and ran the motor for around 3 minutes which allowed the gauge to peg out to the H. Here is what it read on the meter.



So if I am reading things right, this means that my engine temp reading of 59.4 ohms is between "cold @ 73 ohms" and "beginning of band @ 36 ohms" which is listed on the page by John Strenk.
http://home.roadrunner.com/~john.strenk/Gauge%20web%20page/CJSpeedometerGaugeQuickTest.htm
Room Temp�����70 degrees�200 to 400 ohms
C (cold)........................ 130 degrees--73 ohms
Beginning of band........ 171 degrees--36 ohms
Top of band.................. 242 degrees--13 ohms
H (hot).......................... 270 degrees---9 ohms

So it would seem that it is not overheating like the gauge says after all. (Unless the gauge is bad, but I tested that already.) And since it wasnt getting up near 195, thats why I wasnt seeing any flow since the stat was closed. So now what? Is my gauge bad? Is my temp sending unit bad? What do you guys think?
 
#41 ·
Well, if your gauge is reading "H" while the sender is at 60 Ohms, then either the gauge is bad, or the wiring between the sender and the gauge is bad/damaged. 1st thing to check is how well your speedometer is grounded. The Temp gauge grounds through the speedo housing. See the "Good Grief, Grounds" section of Mr. Strenk's troubleshooting page for more details.
http://home.roadrunner.com/~john.strenk/Gauge%20web%20page/basic_troubleshooting_for_cj_gau.htm

As for the sending unit, you really need to know the actual coolant temp to make any definite determination. However, based on the ~3 min running time, I'd say it's probably pretty close.
 
#42 ·
I think we finally got it. I did some more testing using the John Strenk page.

It states: "As long as we are under there you can check the Temp gauge. Only one test. From "A" to "S" on the Temp meter. It should read 12-21 ohms. Same as the Fuel meter from "S" to "A" ."
My temp gauge read 30ohms so something is off.

THEN I also pulled off the thermostat and housing and cranked it up. Coolant blew out everywhere!!!:fear::umbrella:

YAY! Its not the water pump!:banana: And the radiator might be ok too!

I then went ahead and threw the new 195 degree stat in a pot of water and it opens as it should.:thumbsup: Now I need to buy a third t stat gasket and sealant and figure out what to do about the gauges.

I wanted to give a big :thankyou: and :cheers2: to all you guys including John Strenk for all your help and ideas!

Anyone have any luck with the new "in cluster" gauges or have any other suggestions?
http://www.jeep4x4center.com/fuel-temp-gauges-pair-inside-speedometer-assembly-8126919k.html
 
#44 ·
#45 ·
The same situation with my Jeep when I first got it. The fuel gauge did not work, and the temp gauge would peg "hot" after a couple minutes of running.
So, I replaced the water pump, thermostat, and flushed the rad a couple times. Still showed it was overheating, so I starting thinking of a cracked block? or some major mechanical problem....

It was about that time I discovered this website, and noticed the John Strenk website for CJ gauges. On a whim, I tested the temp sender, and it showed it was NOT overheating. Doh! Replaced the fuel and temp gauge, and whamo.... working fuel gauge, and temp gauge showing correct temp.
 
#47 ·
Again, guys, spit out 40 bucks for an IR gun. You can eliminate all the testing by simply finding your what the temp of the water is. they are also handy for exhaust, drivetrain, and even kitchen stove temps.
 
#53 ·
I had this problem after I did my 4.0 swap.

I went through two thermostats, bought an ir gun, and three temp senders. So I figured it was the gauge. When I bought te new gauge it came with a temp sender that was specific to that particular gauge. Swapped it out with the sender in the jeep and haven't had any problems since.

My gauges are aftermarket that were put in by the PO.
 
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