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Engine temp


Russ_S

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What tempature does your jeep run at? Mine gets up to 220. I have flushed the system, replaced the radiator (had a stripped drain plug), replaced the coolant, and replaced the thermostat with a 180. Does an external transmission cooler help with the tempature of the motor?

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TJ4Jim

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What tempature does your jeep run at? Mine gets up to 220. I have flushed the system, replaced the radiator (had a stripped drain plug), replaced the coolant, and replaced the thermostat with a 180. Does an external transmission cooler help with the tempature of the motor?

View attachment 180739
That's a bit warm, have you looked at the fan clutch. Try spinning the fan by hand after the engine is up to full temp (and off), there should be resistance if the clutch is good. Changing the stat to a 180 deg will do nothing to lower engine temps and is not advised.

A trans cooler is a worthy upgrade and will remove some load from the radiator.
 
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CodaMan

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A cooler thermostat can actually make an engine run warmer in hot ambient conditions. The water actually needs time to cool in the radiator, if the thermostat stays open longer which is what a lower temp thermostat would do, it doesn't allow the water to stay in the radiator as long as a warmer thermostat and that can cause temps to creep up.
 
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pagrey

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Be sure you replaced the radiator cap and don't have leaks. Those are really common causes of running a little hot. A few people have had problems recently with a little air trapped in the system making it run a bit hot, make sure you get all the air out. Like @TJ4Jim says the fan clutch is a great idea to check. The 180 is going to cause you problems when things start working again, I'd get the 195 back in there just like @CodaMan is suggesting. Sometimes the thing isn't really even running hot, it helps to hook up one of those cheap ELM327 scanners to the Jeep and see how hot it really is.
 

CodaMan

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If the clutch and rad cap are good, and the ELM327 still says it's a little warm, change the thermostat back to a 195. Even in the hottest days a 195 degree thermostat will keep things cool.

Below is a video of mine at 105 degrees outside and the A/C blasting. Last week it was 110 degrees here and I had the same temps.

 
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Russ_S

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Thanks everyone! I have a few things to look at. I do have a new cap and replaced the sending unit. I also checked the fan clutch and there is a good amount of resistance. It had a 180 in it when I got it. Will change it to the oem 195 thermostat and put on an external trans cooler. Now for a little garage time!
 

TJ4Jim

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Thanks everyone! I have a few things to look at. I do have a new cap and replaced the sending unit. I also checked the fan clutch and there is a good amount of resistance. It had a 180 in it when I got it. Will change it to the oem 195 thermostat and put on an external trans cooler. Now for a little garage time!
Was it a Mopar sending unit, it does matter.
 
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Russ_S

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Yes, one thing I learned early on with TJ's is they do not like aftermarket sensors of most any kind. Do you have the original ?
No. I was on the way to a Jeep event and my gauge was all over the place. 180 to 220 to 260 to 100 in about 10 seconds. Stopped at store, picked up sending unit, and replaced it at the event.
 

TJ4Jim

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No. I was on the way to a Jeep event and my gauge was all over the place. 180 to 220 to 260 to 100 in about 10 seconds. Stopped at store, picked up sending unit, and replaced it at the event.
Could easily be the cause of the current temp readings.
 

Flivver250

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These gauges and sending units are not calibrated to NASA standards, check the actual temperature with an accurate thermometer of your choice. I know you flushed the sytem, I have used the radiator flush "Thermocure" with success. It does dissolve rust in the water jacket that is an insulator. I let the solvent sit in the system for days. For peace of mind, if you flushed the system again, replaced the clutch and waterpump, you'd be about $100 poorer. Is replacing a pump and clutch a bad idea? Well, how old are the parts in your rig? Both are items at the mercy of wear and time. You could go utterly crazy and do the hoses at the same time.
 
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