2004 F150 Heritage 4.6L. 290,000 miles. I recently changed my antifreeze in preparation for the colder weather. While I was letting a coolant flush run through the system per the bottles instructions, I walked away from the truck for 2-3 minutes. when I came back the truck was running hot due to an air bubble I presume. I immediately shut the truck down and checked the truck, no visible damage. I then drained the flush and ran water through the system with a garden hose (I know well water isn't good, I drained the block after.) I refilled the unit with green universal coolant. I made sure to get the air bubble out this time. I drove it around and it does fine up till 75mph. I drove it on the interstate while monitoring the coolant temp with my obd scanner, the temp started to climb at 75mph +. the coolant temp hit 245 degrees, and I pulled over. it immediately dropped to normal, (190-210) I went home and let it cool down, no visible leaks and I'm not getting combustion gasses into the de-gas bottle. I drove it to work the next day, 50 miles one way and it began to overheat on the interstate. I turned overdrive off to bring the rpms up and turned the heater on. The temps returned to normal. I got to work and at lunch I drained the coolant thinking I had an air bubble. I didn't think to save the coolant as I was in a hurry, so I used the coolant the shop uses, red heavy-duty coolant. I read that it is safe for all vehicles, so I just used it. I used the vacuum filler at work to be sure I had no air bubbles. I filled the system and went home after work, heater worked fine and all. temps were above normal but not crazy high. I've been driving it around just fine for 2 weeks in the city and back roads. I usually carpool to work because of the distance, well we got into a multi car accident Monday and had to drive my truck today because the car was totaled, on the way to work at 5am the truck did fine, stayed at 210 degrees at 80mph but on the way home it overheated 3 times, each time I just turned the overdrive off and that somehow kept the temps to 215ish. I saw 249 degrees once and began to pull over but when I slowed down it came down on temp. I eventually drove home with overdrive off, and the temps stayed at 215ish still. This is my first time on this website so be gentle haha. Any advice is GREATLY appreciated, ask away, I'll answer.

 

Water pump prop prob getting bad. They can disintegrate down to nothing....doesn't sound like it's circulating since it's getting hot at cruising speeds. Most of those temps posted are to high.

These motors in particular will not suffer the heat well...be careful.

 

Thank you for the input. I plan on changing the water pump first.

 

Did you have problems prior to the flush?

If not....you may have cooked your engine and have head gasket leak. Gas gets in system and water pump doesnt pump gases....so you lose circulation and cooling.

Any misfire to go with it ...hot or cold?

Coolant temp over 225F is enough to damage engine. When engine remanufactures put heat melt tabs in heads....they use 241F....thats metal temp ..not coolant. No warranty when they show heated past that point.

Hot engine overcompresses head gasket from thermal expansion ...then it leaks at normal temps. Sealing 1000 psi combustion chamber pressure with flat face gasket and sealing surface 1/4" wide .....is almost laughable .....its why head gaskets fail eventually.
.

 

Draining the coolant for an air bubble will just give you another one
You must "burp" the cooling system on those older ones
I believe you will find that your radiator needs to be replaced
That's where I would start

 

Yep, - well water - Iron/calcium contamination and corrosion. Hard to flush that completely out once introduced.

Also, you won't have to deal with any air pockets or hot spots if you fill through the t-stat housing first. Install stat, jack the front up a little so that the expansion tank (degass) is higher than the heater core and you'll NEVER trap air in the system. Nothing fancy full proof way to fill.

To flush everything quick and fast in one shot. Stick a hose with water running (not well water, that can ruin a lot of things), truck running , tank overflowing with the plug pulled out of the rad. Once the water runs clear, it's flushed.

 

I checked the oil fill cap, and it was full of the milky oil that usually indicates a blown head gasket. I can also turn the fan with little to no resistance at all and it keeps spinning. I drained the coolant and I'm going to change the water pump and fan clutch when I can get the money up to buy it from rock auto. For now, I reckon I have to drive my 91 S10 to work, hopefully it doesn't die on me haha.

 

Hope you get it figured out.

Good Luck!

 

From the Ford/Oasis TSB. Had it in the arsenal, I don't use it, the other procedure I put up is quicker imo.

Some might get some use out of it, -

 

Oil fill cap doesnt indicate anything ....they all get milky on underside from trace moisture in cold weather