2001 Escape 3L v6 215k miles, previously single owner well maintained. Have owned since 200k and kept it running sweet.

The other day when I get home it's gurgling so I check under the hood ... yep, definitely boiling. Hooked up the scanner - 214 degrees. Degas tank looks normal level, no perceptible leaks even given the temp and pressure.

Daily driver, and this car temp gauge always runs in the middle including today. I've never driven it with the OBD hooked up so I don't know the "normal" operating temp. Took it out with the OBD showing temps ranging from 210 to 218 and the dash gauge never goes above halfway.

Top rad hose is fat and about to blow and the coolant isn't as pretty as it should be, so I figure beautiful Saturday project:

STEP ONE - flush, new thermostat and new hose before she blows.

After a full gravity drain, and because it's so easy to access, I went ahead and removed the thermostat and ran it for a bit feeding water into the water pump and letting it pump through the whole system (heater core too) until water runs clean, and confirming the water pump is working. Removed and cleaned as best as I can the degas tank too.

Reason for flushing? The coolant I drained had a grayish color and a bit of a weird graphite-like sediment. (Not the sludgy oil-water mixture I'm well familiar with from head gasket issues etc.) Trans fluid is perfect so I don't suspect any issues with leaks between the rad and the tran cooler. So, tstat goes in, reassembly, run it and temps run right back up to 210-215. (Does take a while and as I'd expect I can tell from feeling the top hose that the tstat did open around 190.)

Of course, now I've got a leak. Sure enough, during reassembly the stress from removing the degas tank, now the 1" hose port from that is cracked, and when checked it just crumbles. Crap! Oh well, it's gonna be a beautiful Sunday so my project?

STEP TWO - new Radiator. Pretty easy job altogether. Reassembly, refill, run and burp until it's good and full and are you kidding me temps still hit 218 while driving.

So, now I've done all this work (all necessary so I wasn't "throwing parts at a problem") but now I have questions:

#1 - I simply cannot find a clear answer of what the normal operating temp for this car is. Running at ranges from 210-218? Doesn't seem right.

#2 - this car has suffered from the well documented "coolant light on the dash is on" issue, so I've been checking the coolant levels very consistently just in case but presuming it's just the sensor in the tank. Well, while cleaning the degas tank I tested the float with a meter and oddly enough it works perfectly. Supposedly disconnecting that sensor will make the light go off - also not the case, so now I wonder if the ECU will turn that light on for another reason? And of course I can't find any info about that in the google machine either.

Would love some clear answers, and bonus would be a wiring diagram for the radiator light and associated sensors.

Thanks!

 

The in-cluster gauge is a mechanical idiot light. As long as the actual temp is within operating range, it's going to read mid-scale.

From the Specifications page in the WSM:
Thermostat starts to open (3.0L 4V) 90-93°C (194-200°F)
Thermostat fully open (3.0L 4V) 106°C (223°F)

 

The temperature you see on the scan tool is the cylinder head temperature, right? That would normally be higher than the coolant temperature.
What are the current symptoms, bubbling, boiling, burping, upper hose about ready to pop?
I am pretty sure the temp gauge on my 3.0 is not an idiot light type as it will move slowly to the normal operating temperature indication. I'd think a idiot would be 'on/off', with a fixed resistance. There's no need for that as temp sensors are old, reliable, and cheap. Single wire installation on the assembly line. Oil pressure gauge is more likely to be 'idiot gauge', and has been on a lot of Fords.
I'd not worry if the temp is within the bounds noted above, and all noises are to a minimum, but do pay attention to the gauge if it starts to move above previous normal.
Has the coolant been maintained? Why was the radiator replaced? Is the new radiator of similar capacity to the old one(same number of rows of tubes, size, etc)?
tom