Water Pump and Temps have me stumped...

[EagleChief]

I was able to use the stock water pump for about 8 yrs and 140k +/- miles. Changed it out 2 yrs ago with no issues. Now, a week ago, I noticed a leak from the "new" water pump. Ordered a new one, new coolant, and a V6 E-fan for that conversion.

Changed out my water pump last night. Put the V6 E-fan in and topped off the coolant. I let the truck run for a while and get up to temp with the radiator open to work any air out of the system and to verify that the fan would kick on (it did). Once I felt like I got all of the air out, I went for a short drive - maybe 2 miles. Temps started creeping up on me again. It got up to 240F within those 1.5-2 miles that I drove. Temps were up to 220F before I started driving, which I assumed was normal. Parked the truck and shut it off and went to bed - it was late - assuming there was still air in the system.

Before leaving for work, I topped off the radiator with some more coolant. Drive to work (about 23 minutes) and the temps still got high on me. The fan came on, but I still got temps of up to 250F, enough to get a warning. Then, they started dropping down to about 234-236F. I'm assuming there is still air in the system, I'll check again in a little bit after the engine cools off.

When I changed the water pump before, it was no issue. Now, I'm stumped. Any thoughts?

 

[Burla]

I'd drop a 180 t stat and see if the numbers don't come down. Was there a reason for the swap, have a historical issue with temps?

 

[Ken226]

up to temp with the radiator open to work any air out of the system and to verify that the fan would kick on (it did).

Once I felt like I got all of the air out, I went for a short drive - maybe 2 mild. Any thoughts?

So, by "with the radiator open", you mean you removed the plug in the water pump to burp the system?

Or something else?


Like this?

how to bleed coolant system on 5.7 hemi

Watch how to bleed coolant system on a 5.7L #hemi in a chrysler 300c with #moparbro fred_eazy21 This coolant bleed and fill procedure also applies for the 6...

youtu.be

 

[EagleChief]

I just went back and looked at my past order from 2 years ago. I put a 180 t-stat in 2 yrs ago when I changed the pump the first time. I may have committed a cardinal sin, as I did not replace it this time since it was only 2 yrs old.

No real reason for the fan swap, other than pulling that extra strain off of the water pump, since it seems they don't last near as long as they used to. I can't say that I've watched the temps all that much. But, when I have looked, 220F is about as high as I've seen it.

I do have the active shutters, but that really shouldn't matter that much, I wouldn't think. They haven't been an issue in the past.

 

[EagleChief]

So, by "with the radiator open", you mean you removed the plug in the water pump to burp the system?

Or something else?

I left the radiator cap off while the truck was warming up. I actually forgot about the plug, until I was watching some videos after the fact, before I went to sleep.

 

[Ken226]

Try it using this method

how to bleed coolant system on 5.7 hemi

Watch how to bleed coolant system on a 5.7L #hemi in a chrysler 300c with #moparbro fred_eazy21 This coolant bleed and fill procedure also applies for the 6...

youtu.be

 

[EagleChief]

Try it using this method

how to bleed coolant system on 5.7 hemi

Watch how to bleed coolant system on a 5.7L #hemi in a chrysler 300c with #moparbro fred_eazy21 This coolant bleed and fill procedure also applies for the 6...

youtu.be

Yea, I'll try that this evening when I get back home.

 

[EagleChief]

Got home tonight and checked the plug on the water pump. Pulled it out and coolant came gushing out. Made a mess all over everything before I got the plug back in. Added some more coolant to top it back off. Took the new fan off and put my original fans back on, thinking maybe that's it. Went for a drive and the temps starting climbing back up. Drove a little further and then jumped on the highway. By the next exit (3/4 mile), I was already up to 240F again. Got off the highway and took it easy back to the house. On surface streets, it was a steady 235F for the most part, then dropped down to 231F. I got on it hard from a stop sign and it climbed back up to 238F before I slowed again to turn into our neighborhood.

I guess the next option to try would be the thermostat. I'll pick one up tomorrow and try it all again.

 

[Barr2255]

Got home tonight and checked the plug on the water pump. Pulled it out and coolant came gushing out. Made a mess all over everything before I got the plug back in. Added some more coolant to top it back off. Took the new fan off and put my original fans back on, thinking maybe that's it. Went for a drive and the temps starting climbing back up. Drove a little further and then jumped on the highway. By the next exit (3/4 mile), I was already up to 240F again. Got off the highway and took it easy back to the house. On surface streets, it was a steady 235F for the most part, then dropped down to 231F. I got on it hard from a stop sign and it climbed back up to 238F before I slowed again to turn into our neighborhood.

I guess the next option to try would be the thermostat. I'll pick one up tomorrow and try it all again.

Definitely try a new thermostat first. If that doesn't fix it maybe go rent a pressure tester for the radiator that way you can rule out any leaks that aren’t allowing the system to build up enough pressure.

Assuming fans and shutters are working proper. If pressure holds the only thing I could think of is to either try a new water pump or try an do some good flushes of the coolant system.

 

[GPx0]

Start with a cold engine.
Start it up and let it idle.
Feel the upper and Lower radiator hoses every couple of minutes while watching the temp gauge.
The upper hose should warm up first.
When it reaches the open temp for the thermostat, the lower hose will quickly heat up to about the same temp as the upper hose.
If your temp gauge hits 190-200F and the lower hose is still cold, you don't have water circulating. The thermostat is stuck closed.
I would shut it off at 220F. I wouldn't let an engine climb up to 240F

A simple test to confirm is to remove the thermostat (after it cools down) and repeat the test, but I wouldn't run without a thermostat. Engines run hotter without them.

 

[04fxdwgi]

Fun fact. Always replace the stat after an overheat..

 

[EagleChief]

Picked up a new thermostat and some more coolant on my way home last night. Swapped the thermostat and all is good! Kicking myself for not replacing that in the first place. I knew better. Highest temp I saw while on my test drive was 196F with a mix of streets and highway for about 6 miles or so.

Sorry for an unneeded thread when I should have done what I was supposed to do in the first place.

 

[turkeybird56]

Picked up a new thermostat and some more coolant on my way home last night. Swapped the thermostat and all is good! Kicking myself for not replacing that in the first place. I knew better. Highest temp I saw while on my test drive was 196F with a mix of streets and highway for about 6 miles or so.

Sorry for an unneeded thread when I should have done what I was supposed to do in the first place.

Just better you were able to work through the issues and find the culprit, that dastardly thermostat. You do know the thermostats not been as good as in the past, so just be aware.