Overheating

[coachjohnopr]

Have 2017 ram 1500 3.6l. Truck is running hot 245. Only thing not changed is the electric fan. I hear it turn on and the it sounds like it powers down a few amps. I 4hink fan is going bad or relay is bad. Any ideas.

 

[crash68]

Describe the conditions that the truck is hitting 245°F ?
Are you sure you've bleed all the air out of the system? It's possible the thermostat is bad even if it's new.

 

[coachjohnopr]

Regular driving. Tried with and without thermostat. Everything but fan is new.

 

[coachjohnopr]

So I think it is electrical. I am swaying toward corrosion in the fuse box. Reason is the ac fuse in box has melted from heat. Going to fix what I see and then go from there. When fan turns on you can hear it power down a little.

 

[jws123]

Stop driving it until you fix it keep overheating it like that your going to warp head and blow gasket.

 

[star_deceiver]

Are your grill shutters stuck in the closed position?

 

[Peter Albert]

I stumbled across this thread today because of something that happened today 8/1/2022, in regard to overheating, and I wanted to see if anyone else was experiencing this. I have a 2017 1500 3.6L 4x2. I drive approximately 65k miles a year. About a year ago, I started getting the overheat warning. Because of the number of miles I had on her at the time, I got a complete cooling system re-do. New radiator, new fan assembly, new hoses, new belt, new water pump, new thermostat, new temperature sensor, and of course fresh clean Mopar coolant, properly bled to remove all air from the loop. A year later, the overheat warnings continue. As of today, I have 250,305 miles on her. Also today, I saw both the digital and analog gauge temps reach the highest I've ever seen, 259º and just shy of the red line! Yes, two hundred fifty-nine degrees. I called my mechanic who asked if I was seeing any steam or any fluid draining out. Nothing. Clean and dry. He told me he suspects a PCM issue and that it was not actually overheating. He asked me to come over right away so he could plug in the PCM with it as hot as it was. Keep in mind that he has been trying to figure out this issue for a year now, to no avail. When I got there, the first thing he did was use his laser infrared thermometer to check numerous points on the radiator, hoses and engine block. ALL of the readings were within normal operating range. Not a single one was even at the high end of normal, yet the digital and analog gauges were still showing extreme overheating. The overheat idiot icon and the "message" system both disappear after the temp drops below 250º, so there is nothing he can reset with his code reader. He had his diagnostic pad plugged into the computer, and it also showed the same high overheating temperature that the digital gauge showed. But again, the physical, actual temperature of the idling engine and radiator were normal. As we have changed the temperature sensor twice in the past year, along with confirming the connectors at the sensor and PCM are not broken, that this confirms an issue with the PCM. The next step will be to do a hard reset of the PCM. Not just the simple 'disconnect the battery for a few hours' type of reset, but the one where the main connectors on the PCM are disconnected at the PCM, and another computer is hooked up to it to reinstall the software and/or firmware. He said this also adds updated software/firmware which might address a know temperature gauge reading. If this doesn't correct the false temperature readings the PCM is sending to the digital and analog gauges, he says the next step is a new PCM. There's a company here in the Los Angeles area that drives to the mechanics shop with all the computer equipment, latest software and proper cables to do the job. I have an upcoming appointment. Look for an update in a few weeks. I want to put some miles on her to see if that reset fixes the issue.

 

[Peter Albert]

The computer update and reset did not fix nor even help with this issue. The truck is still giving the engine overheat warnings, and even indicates temps reaching 262º ! However, the engine is NOT overheating at all. The analog gauge can be buried in the redline, and the digital gauge can be showing 255º, yet using a laser thermometer to take temperature readings all over the engine block, radiator, hoses gives readings indicating the engine is operating at normal temperatures. So these engine overheat warnings are false. I HAVE replaced the temperature sensor. That changed nothing. Knowing the engine is actually fine, I wish I could figure out if there is a fuse I can remove to stop the never ending DING! DING! DING! warning alert. It's not an obvious choice on the fuse block list.