The proper thermostat is a 192, so 189 is not a concerning temp if that's the hottest it actually gets.
The gauge is reading higher than you're used to seeing but still in the normal range.
But you're not used to seeing it move which makes you nervous because it's different than what you normally see; which is about all that gauge is good for - it's not really an accurate indication of actual engine temperature.
you could get a real gauge that screws in where the sender goes (you did change the sender, not the sensor, right ?) even just to use long enough to determine actual engine temp.
All that said, I'd suspect air in the system, a faulty sending unit or gauge, a faulty clutch fan, missing shroud, and if all that fails you'll probably have to mess with that thermostat just to be sure; though I can understand you wanting to do that last.


P.S. I've got that same bumper on my truck. Was the diesel cooling bumper in 92 till they figured out it looks so cool that they put it on the Eddie Bauer models.

 

The level in your overflow bottle should rise slightly when hot then go back to a lower "cold" level as it cools down.
Checked that hose and bottle for restriction ?

And air in the system after a radiator change is quite possible.

 

​​​​​​​We've evacuated air from this thing's system for Some time, and I haven't been able to get air out for a while, now. I think it's good (I hope, anyways. I'm following Ford's "burping" procedure each time.) The hose and bottle were checked and we're found to be clear. One of the burping processes, I released the hose from the top of the radiator that goes to the coolant reservoir and allowed the truck to reach operating temperature (even drove it around the block a couple of times like that), and when I opened the hood and checked, I was getting a couple of bubbles out of it here and there, but no water dripping out from it. Allowed it to cool the same way, and still nothing. Somehow, I don't think the system is building enough pressure to push the rad cap open, but these symptoms are present on all three of the caps I've used (just one I took the hose off to see if it would push some coolant out and it didn't). Any ideas why it would do that? I'm partly convinced it may indeed be running at a safe temp, based on what you said, because we shot temp right at the heads and it came back with the highest temp, which was 189°. Just I'm not used to seeing the gauge move around like it does, and get as high as it does, but according to the laser reader, it is reading safe temps. Just disconcerting since it never did it until this radiator. I'm going to do Steve's procedure for checking the radiator for cool spots and see what we can come up with. It would be nice to know that it is indeed the radiator, as it has limited lifetime warranty, so I can hopefully return it for either another Murray, or better yet, get one from another place, and try again. But then again, it would be nice too to find out that I had a plugged (insert item here) or a (insert random problem here) that could literally be handled in a couple of minutes without the hassle of replacing the rad. But until then, I've got to see if that rad is leaving cool spots. Also, see if I've got flow through literally every exterior hose. If they're all hot/warm at operating temps, and firm, I should know then that I have flow throughout, minus the coolant reservoir, of course.

 

When you released the hose from the top of the radiator that goes to the coolant recovery bottle, did you have the radiator plum full of coolant with the engine cold? If you did you should have had coolant come out there when the engine warmed up.

If the radiator was about 2 or 3 inches from full when the engine was cold, the radiator would act like an old style radiator without a coolant recovery bottle. Ie the radiator would just get full when the engine got to operating temperature, and cool to 2 or 3 inches from full when the engine got cold again.

 

It doesn't sound like you read that cooling system article. It explains about air & the overflow tank. It should purge SOMETHING into the tank almost every time the engine runs; especially after topping up in the radiator.

When the WP was changed, did you look inside the old one to see if there was anything wrong with it? I've never seen flow inside a radiator neck, unless the radiator is severely blocked by sediment AND the t'stat is stuck open or removed.

Pressure is not flow, and it is not caused by flow. So feeling pressure in the hoses does not indicate that there's any flow through them. The entire system (excluding the overflow tube & tank) should pressurize as the engine warms up, even if the WP isn't turning.

But I have ZERO faith in "hi-performance" parts of any type, and that "hi-flow" pump doesn't look like it's capable of any more flow than a stock pump. I bet if you compare its impeller to the original, they're identical. What I'm really curious about is if it's even built with the correct rotation for an EFI. One of the reviews mentions reverse rotation, but you never know what that person considers "standard" rotation.

 

Steve, I did not know that about the difference between flow and pressure. And yes, we did take the old WP apart, and to be honest, aside from the bearing getting a little stiff, the impeller was all there, and didn't appear to be in any bad condition.

I know what the system should do, and on the old radiator, the system operated properly. Aka, it rose and fell as it should. The reason we even got rid of the old one was because it developed a crack, and leaked out all its contents in a matter of 2 hours. (Granted, it was the original radiator, so props to it for surviving so long). This new radiator though, like I mentioned, does not fill the tank when hot, nor lower when cold.

I did try something tonight. I turned my heat on. When I did, I noticed that the temperature was not all that hot. I had it on max fan, max heat, thinking I may see a slight change in the gauge. All to no avail. But I mention this to say, the heat was indeed warm, but not hot. Certainly not as hot as it used to be, and with where the gauge has been resting lately, I would have thought that it would be scalding hot. But it was just a shade above lukewarm. I also noticed the sound of water running in the heater core, a clear indication of air, however, the radiator has been full every time I check it. So, I don't see how air could be getting in there? I burped the system via Ford's specs, including having the heat on as high as it goes. Multiple times, just to be sure. Do you think I have a heater core blockage? And if so, do you think that this could cause my high operating temperature? I'm eventually going to check and see if my thermostat is operating properly as well. Just don't want to with how the holes have been tapped and died and a flat mating surface no longer exists, so a high amount of gasket sealer has to be used now to make a proper seal. Nonetheless, I fear this too shall be in the near future for this truck.

At any rate: Given the above info, is it possible that the heater core is blocked? Would this in turn cause the higher operating temperature? I HAVE read the information given via your link, btw. Additionally, when I let the cap loose slowly (but NOT off), whilst running, it WILL vent into the recovery tank. But if the cap is properly tight, it seals and does not allow flow of any sort. Just for sake of reiteration, this cap operates the same as all previous caps on this radiator, including an 8lb cap. Aka nothing flows in or out. Another thing: The cap is always cold. Always. Never hot. Even after engine has been running for an hour or more. This is an observation I just remembered I noticed the other day, and having thought about it, I've never had to barrier my hand to touch it. One more thing: I have not only checked for blockages between the recovery tank and the radiator, I have recently (as of the radiator change) cleaned the tank itself, and the hose. Part of the flush I did. I wasn't going to leave the tank dirty and have a brand new radiator in there. Regardless, if the cap is off and the vehicle is allowed to run, the recovery tank, at that point, will fill to its heart's content, considering the cap is not stopping flow into it.

So my final thoughts at this point:
1) Possible blocked heater core
2) Possible that the radiator is blocked/deformed in some way
3) Possible defective thermostat
4) Possible that this water pump is not working properly, simply because Steve has a lack of faith in it, and thru his observation, has instilled some doubt in my mind about it being right, although it says it's supposed to spin "counterclockwise," and it indeed does on my belt. But that doesn't mean anything. I'm going to have to see if I have any warranty on either the radiator or the water pump.

Is there a way to test the flow of the water pump without removing it? I'm curious to know if it is pumping the wrong direction. It should flow TOWARDS the top hose, based on my understanding of the information in that link, correct?

My apologies for this long-winded post. Just trying to be as descriptive as possible.

 

Yes, indeed it was chock full. I'm not sure what its deal is why it won't allow flow to the recovery tank. It WILL if and ONLY if I make the cap loose. Not removed, but in-between properly seated and unlocked. It will then allow flow, albeit a very small amount. But properly seated, nothing goes in, or out.

 

It's not "getting" in there - it's IN there. You're not getting it out.Exactly what procedure did you use? Be specific & thorough.That only applies to vehicles with a heater control valve - these trucks don't. They only have a temperature diverter door. The heater core should always be the same temp as, or hotter than, the radiator. So the temperature setting has no effect on coolant flow or air bleeding.If there was, you wouldn't hear coolant flowing. No, the heater core is not necessary for engine cooling. Nor is flow through the heater core loop.That article explains how the t-stat should work during the radiator sediment test. So it CAN be tested in-place.That makes me suspect the radiator HOSES moreso than the cap or radiator or heater core or WP. If the hoses are too soft (elastic), pressure never gets high enough (higher than the cap's rating) to vent, and there's never enough suction to recover coolant from the overflow tank. Check all the soft components for swelling when the engine is hot. Or get a pressure tester, and check it cool.


(phone app link)

If you get the full kit, you can also test the cap's actual pressure relief.That & the cool heater core suggest the WP isn't pushing much (if any) flow. With the engine COLD & off, disconnect the heater hose AT the firewall that comes FROM the intake manifold (not the water pump). When you start the engine, it should immediately shoot a jet of coolant out of that hose (so be prepared to catch it, if it's good coolant).That tests the lowest level of the WP's flow capability, but not its full capability, and not so much the impeller direction.Even with the wrong WP & timing cover direction, the coolant will always flow in from the lower hose, and out to the block. It's a centrifugal pump, so spinning backward is just less-efficient - it won't actually create reverse flow. Just like a squirrel-cage blower in an HVAC system.

 

I greatly appreciate the detailed reply! I will run these tests and look over the link you sent again for that test of the thermostat. It won't be till later this week, but again, thank you. I'll let you know what I find.