Hey all I’m new here and I’m scratching my head. I’ve got a 10 ram 5.7 with 194,000 miles that recently started to over heat. Ran up to 240 degrees. Noticed the coolant was a little low not much. I replaced the thermostat bled it out which is a pain in the ***, found that it wouldn’t go over 197 degrees. The next day it overheated again, it went up to 240 then would go back down to 195 then would go back up to 240 and stay there for a while, then it would go down to 225 then back up. The next step I took was I replaced the radiator cap and the same exact thing it was fine driving home but let it get cold and it will over heat. So I went drastic and replaced the water pump and the same thing. I also noticed that I’ve a cylinder #4 misfire. One other note I just had the intake plenum changed out but I don’t think that oils cause over heating problems. If you have had similar problems please let me know thank you!

 

Maybe still an air pocket in there somewhere?

Maybe a failing temp sensor? (lying to you about what temp the engine really is....)

 

Hey you, I beld the hell outta that motor, I feel like it’s getting air bound when it gets cold.

 

After doing the t-stat and water pump I took out the coolant temp sensor and poured coolant in til it came out the hole. I then parked it on an incline and beld the hell out of it. I had to idle it up quite a bit to get it to the 203 degrees so the thermostat would open and I could allow to bleed and add more coolant.

 

Is it sucking in air from the overflow tank? (I am not real familiar with the cooling systems on the newer trucks.... wish I could be more help.)

 

**** I didn’t think about that it could be I guess. I’ll have to check in the morning and see if there’s coolant in the Reservoir thanks hey you

 

Hey all so it’s dec 18th 7:30 am checked the coolant level this morning I didn’t see it at the top of the radiator so I added a tiny bit (that’s all it took to be full) I checked the over flow there was coolant in there. I started it up let it idle for about 20 minutes it was around 150 degrees I got in the truck idled it up around 2000 rpm once it got to 170 the temp went up fast. All the way up to 230. Barley any heat at all. It currently idling at 226 and the top radiator hose has zero pressure in it. Help!

 

Something is wrong there. (yeah, thank you Captain Obvious......) You still have an air pocket in there somewhere. Not building pressure also indicates the system is not completely sealed.

 

Should I pull the thermostat out fill the system and do a pressure test and see if I can see any leaks?

 

Pressure test first, and see what happens.