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Check Gauges - Temp Gauge hits Max

10K views 21 replies 6 participants last post by  badrc 
#1 ·
So today was 100 degrees and I was in stop n go traffic. I had the A/C going and I noticed the temperature needle 3/4 of the way. You can see it kinda wanting to go more but then it stays where it's at. All of a sudden it maxes out and the check gauges light turns on. I pull over and turned off the a/c and the temp returns to where it was. This continued to happen 2 more times till I got home. This started to happen after the radiator was replaced 2 years ago. Any clues where to start to find the issue?

I have already replaced water pump, thermostat, and temp sending unit.

Thanks
 
#2 ·
Was the t-stat changed? If not id do that asap as well as the fan clutch.
 
#3 ·
He already said the T-stat was changed.

If I were you I'd have a look at the fan clutch, but this sounds more like an electrical gremlin then anything else. It sounds like a wire gets complete ground every once in a while so the temperature pegs like its supposed to.

Mines a 95 so I can't help you since our gauges are wired differently, but I'd try unplugging the battery and cleaning the terminals of the pcm, and then unplugging and replugging the sender, then finally reconnecting the battery.
 
#4 ·
Missed the part about the t-stat
 
#5 ·
Unsure if this has anything to do with it but a while back while driving at night the dashboard light flickered and then turned off momentarily. The gauges did not stop working during during the short outtage. Anyone think the gauge for the temp might be bad? Temp readings were still acting up before this.
 
#6 ·
Its very possible the gauge is bad
 
#8 ·
You can swap the temp gauge over however i have never seen anyone selling just the gauges. You can get a whole cluster for around $25 shipped if that on ebay. They dont go for much.
 
#10 ·
SouthSeaPirate, list what you have replaced from start to finish.
 
#11 ·
Thermostats - Many times throughout this list

Radiator - old one literally fell apart
Clutch Fan
Water pump
Thermostat housing
Lower, upper and heater hoses
Water pump again
Clutch Fan again
Lower hose again

Ive also burped the system using a couple of different but recommended ways. Ex, Down hill fill, uphill fill, taking out temp sensor, etc...

I shouldn't say it'll never get fixed, that was totally nonconstructive. Sorry bout that.
It just seems the minute I fix one, another thing fails. And it will still overheat in traffic with AC on no matter what I do...
 
#12 ·
One thing to check is the lower hose. OEM hose had a spring in it to stop it from colapsing. I have never found an aftermarket hose with a spring in it. I always transfer the spring from the old hose to the new hose. Also flush your heater core in both directions and make sure your fan shround is on properly. With the radiator out use a hose to flush the condensor in both directions. They are known for getting caked up with crap over the years and blocking air flow. Are you always using the same brand t-stats? Have you tried drilling a small "weep hole" in the t-stat to allow constant flow even then it's closed?
 
#14 ·
My problem with stats was they were opening too soon and it wouldnt warm up while driving. Ive used many brands of stats, including fail safe... I havent done the drill thing yet as it was never a closed stat issue.

When I changed out the rad the condenser was fairly caked but I did clean it then. Could be caked up again, just really dont want to take out that shroud for the billionth time :(

It was 108 here today, I let mine idle on a black top parking lot for 30+ mins to see if it would get hot. It barely and slowly climbed almost to the mark past 210 and kinda just stayed there. At any speed moving down the road or in a parking lot it will stay just under 210.

Looks like you have done about everything, have you checked your A/C condensor to make sure its not clogged with debris. I have also seen a bunch of debris accumulated between the radiator and condensor restricting airflow through the radiator.

I had been fighting mine running hot, and I have a fairly new rad, w/p, therm, hoses etc. What I think helped mine was a bottle of water-wetter and I leaned the antifreeze out to about 1/3 coolant & 2/3 water. I checked freeze protection and its rated to just under 0*F which is probably ok down here, but I might drain and add about half a gallon before winter.
Ive tried the water wetter and other additives before, and I couldnt tell if they worked because shortly after I was draining again. I may try that again when I verify that everything else is taken care of.

Thanks guys!
 
#13 ·
It was 108 here today, I let mine idle on a black top parking lot for 30+ mins to see if it would get hot. It barely and slowly climbed almost to the mark past 210 and kinda just stayed there. At any speed moving down the road or in a parking lot it will stay just under 210.

Looks like you have done about everything, have you checked your A/C condensor to make sure its not clogged with debris. I have also seen a bunch of debris accumulated between the radiator and condensor restricting airflow through the radiator.

I had been fighting mine running hot, and I have a fairly new rad, w/p, therm, hoses etc. What I think helped mine was a bottle of water-wetter and I leaned the antifreeze out to about 1/3 coolant & 2/3 water. I checked freeze protection and its rated to just under 0*F which is probably ok down here, but I might drain and add about half a gallon before winter.
 
#15 ·
Another thing to check may sound silly but make sure your fan blade is bolted to the clutch in the proper direction. If it was installed backwards its actually pushing air rather than pulling. Kinda like running an electric fan in reverse.
 
#18 ·
cool days doesnt mean it wont over heat. The risk is you have no idea what the engine temp is and yes overheating can cause serious damage. Replacing the cluster is easy. About 12 screws and its out.
 
#20 ·
Keep in mind mileage is stores in the cluster so if you change the cluster out it will reflect the mileage on the doner Jeep. Best thing to do to avoid issues with inspection, sale, people thinking your trying to scam them if the mileage is lower, all that crap is just swap the gauge over not the whole cluster. Save the doner cluster for the rest of the gauges. Never know what you may need in the future.
 
#21 ·
I have yet to replace the cluster. I have taken video of the car parked when the outside temperature is over 90 degrees F. I had driven over 30 miles and I let the car sit in the parking lot with the a/c . The temperature needle was halfway and it hit max within 5 minutes. Driving home the temps were down. I luckily have not had to sit in trafffic.

Here is a short clip of what happened while sitting in the parking lot.

 
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