I read this thread and have pretty much identical symptoms.. https://www.ford-trucks.com/forums/1...ing-issue.html


A few things to note about my truck:
1. I did the injector cups back in April.. so no diesel in the coolant now.
2. just swapped out the thermostat last night and put in another Ford OEM one. (resulted in no change in symptoms)
3. coolant looks fine..
4. heat in the truck only when I rev the engine.. (this indicates low or no coolant circulation to me)
5. same bubbling sound from upper radiator hose
6. upper radiator hose seems void of coolant most of the time even when hot.
7. checked the radiator for flow using garden hose and it seems fine
8. I thought the fan clutch was not working but did hear it kick in yesterday as I was watching the degas bottle, and felt all the extra air flow as well.
9. I have not pulled and checked the water pump (it does not leak)


could the diesel in the coolant from prior to this past April have caused some damage to the water pump?


Seems like there is some circulation improvement at higher RPM's.. but have no way to validate..


Really need to figure this one out as I'm supposed to go on a trip next weekend and need my truck for it.


Thanks,
Andy

 

Have you checked to see if the heater core is possibly plugged?

 

Sounds like you need to pull your water pump to see what kind of shape the impeller is in.

At this point anything is a guess.

I have pulled my cooling system apart a few times and re used the coolant, just drain it in to a 5 gallon bucket and strain it through an old tshirt to catch anything that may have fallen in, and keep a gallon of premix to top off because you can never get it all.

 

rented the fan clutch tool kit today from Advanced Auto. If I need a new pump, i want to get the motorcraft brand or the one from Clay.

While I have it out, I'm gonna flush some water through the block and heater core to see what comes out... hopefully nothing will come out and a new water pump is the answer.

 

Here's what my fan clutch tool looks like, with a flat chisel in it. One short burst is all it takes.

 

Check the front of the radiator behind the IC. They tend to trap dirt and debris.

Also, before pulling the pump, use an IR Thermometer on the Rad Core to ensure you don't have a blockage. Easily identifiable this way.

Seen both of these many, many times.

 

I have one of those... where do you place chisel /hammer?

 

I went ahead and bought the real Navistar/ International brand water pump... that looks like the real deal... there are a few mods to install it, but it looks more robust and it has a coolant filter..

 

As you face the truck and you look down at the big nut for the fan clutch hit it on the left side of the nut. Mine knocked loose incredibly fast.

 

The chisel does leave some scarring on the nut.

There can only be one cause--water pump. Since the hose does not feel like it has coolant flowing the pump cannot be working. The hose from the bottom of the degas bottle does a good job of filling the system, but only if the water pump is working.

If the impeller and/or pump housing is damaged by corrosion/contact with abrasive silicate particles, the ability to move water is severely reduced. The outlet pressure of the pump has to be high enough to push out trapped air in the system and push water through the heater coil which is above the pump.

 

Mechanic friend did the chisel hammer on mine but I wasn't a fan. Just take the inspection plate off of the transmission and put vise grips on it to keep it from spinning.

 

So I put in the new water pump... Went ok, but the NAPA lower hose did not fit so I had to find a suitable alternative...

The heater in the cab is better but I can tell it's hotter at higher rpm's.

I am still getting the same symptoms near the thermostat. Sounds like boiling water / bubbling ..

I am leaning towards the water pump not being the cause. The old one seemed fine and showed no signs of wear that I could see. So I think I just spent a day about about $300 for nothing other than ruling out the water pump.

I have been researching and read that the oil cooler can get clogged up... Could this be my issue?? Heard its a real bitch to get out too.

What about the Dorman after market cooler? is it junk? That seems to be the only one local for pick up. NAPA has one that is their brand but who makes it?

 

This can quickly and easily happen if you are not careful. It is best to properly diagnose then fix. I would recommend an IR thermometer and you can see exactly what is hot and what is not. I got this one and I like it. It is more expensive than many but I have faith in the Fluke name and I like quality. Others may have cheaper ones that they can give reports on.

Fluke 62 Max Infrared Thermometer, 30 to 500 C & 10:1 Spot Size ratio | eBay

 

It sounds like you could possibly have the wrong thermostat. Have you checked to be sure you have the correct "long stem" thermostat? If there's a short stem thermostat installed coolant will not flow to certain areasareas of the engine.

 

It says in the mod instructions to use the short stem...