Overheating help!

[jirk41]

2004 ram 1500 5.7

I'll try to simplify as best i can.
Started overheating, went home, let it cool down. Checked everything out, looked good. Figured I'd just swap the thermostat, maybe quick fix. Put 203 degree stat in

After thermostat, ran too cool, halfway between cold and mid point.

Started to suspect temp sensor, but borrowed a friends temp gun first. Running 178 F at the head....hmm.

Decided to reinvestigate thermostat. Turns out, 180 degree stat in a 203 degree box.... whew, easy fix. Got correct thermostat and installed.

After 2nd, but correct, stat... running warm again(don't think it's been actually hot, but getting at least halfway there). WTH it's going on?

Additional info;
Engine was replaced with jasper reman about 9k miles ago, so i ruled out water pump as it is still young, and coolant is flowing.


Any idea?

 

[moezer]

If theres any air in the system then it will over heat. Also check and see if ur fan clutch is still good they tend to fail when ever they want kinda thing

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[jirk41]

clutch fan appears to be functioning properly, is the bleed for the coolant behind the air compressor?

 

[moezer]

Try stopping the fan with some flyer or news paper while it's on if it stops then it's bad

Take the rad cap off and let it run

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[grpht03ram]

Where is the needle on the coolant temp gauge?

Does the temp warning light turn on?

EDIT: After re-reading your post it sounds like the gauge is getting to 3/4 of the way; In between middle and the red?

 

[LoneWolf3574]

There is no bleed needle on a Ram 5.7L Hemi, the radiator cap is literally at the high point in the cooling system. Is the thermostat clocked correctly? The little hole should be at the 12 o'clock position for the best performance. With the needle pointing at the midway mark, your temperature will be ~210F. With a 203F thermostat, in Arizona, the ambient temperature around 107F, my truck holds the temperature at 208F, any ambient temperature under ~100F and the coolant temperature stays pretty close to 203F.

EDIT - Just as an FYI, the last time I did a complete drain and fill of the coolant system at my home, I still ended up topping off the overflow with about a quart about a week later. It may take a few heat cycles to fully get all the air out of your coolant system.

 

[El Guapo Phil]

I want to add my 2 cents to the thread. I had to replace my radiator a few months back. Installed a 180 stat to see how the Ram would run. All seemed good to me. The medium term was about 195. I thought all was good. Then the motor began to get hotter on longer hilly trips in Belize. On a trip to the coast, the temp would climb to 235. There had to be something wrong.

Decided to get a new stat in the morning after returning, all the while nursing the Ram on the 2 hr drive. Checked the radiator reservoir, it was full. Pop the radiator cap and had a feeling the radiator need bit more coolant. I had to add ¾ gallon. Yes, that much.

I realized the shop that installed the radiator and did the bleeding did not know about the Ram needed to be in an incline to properly bleed the air out of the system. It took time for the Ram to finally get enough to the air out and me checking the coolant in the radiator, not only the reservoir, to solve the heating up problem...very low on coolant.

Test drove the Ram while checking the radiator temperature, it read 180 to 188 while going up and down hills. Put it 4x4 and when up a steep drive. Stat read 190. The panic I had the last few days is all gone.

I learned to double check whatever the mechanic shop did if it is at all possible.