Afternoon!

I have an 11 F350 6.7. It has just under 200K miles on it. The other day I was driving home, about 100 miles, and my truck's temp spiked. Not like a little spike, but jumped to the 3/4 mark(if there was one) then slowly kept rising to to the overheat mark. I pulled off onto the hard shoulder waited an hour or so to let it cool down, then finished the drive home. All the way home my temp gauge seemed like it was on some sort of drug. It would jump a needle width when I would have to accelerate, then slowly cool to normal after I got up to cruising speed.

I'm confused. Any takers wanna help me out with this? Up until this point this truck has been exceedingly reliable. I pull a 13k 5th wheel once a month and drive about 40k-ish miles a year.

I also had to refill my degas bottle up to the fill line. Took 2 gallons of Ford VC-3-B Coolant and water mix. After a short run to verify the problem, it took another 1/4 to 1/2 gallon of mix. But, no everheating. No signs of leaks anywhere. Just a strong scent of coolant on shutdown outside the truck. Pressure tested the cap, I don't have a way of testing the system pressure. Anyone got any ideas?

Data from Autoenginuity:

Engine Oil temp 195-202 Degrees
Engine Coolant #1: 188.2-199.5 Degrees
Engine Coolant #2: 125.5-129.9 Degrees.

I have the full CSV file if anyone would like to see it.

Thanks in advance!

 

here you go my 6.4 did that

 

At this point I will definitely give a cap a shot. Thanks! I really would rather not spend $3K or more to replace stuff that doesn't need to be replaced.

 

That is a lot of coolant loss. During the overheating episode, did you see any steam or liquid anywhere? Erratic temperatures might well be a thermostat, but it sounds like you have lost coolant over time and it finally reached a point where circulation was lost. The coolant either came out the overflow from overheat, out thru a leak that you should have seen or worst case an internal engine problem like a bad head gasket.

Have your oil checked for coolant, thermostat replaced and a pressure test done possibly by your dealer.

 

There was no steam or obvious boil overs. I just did an oil change the day before and have been watching the oil to see if my truck suddenly starts to make oil or turns color. Like water in oil. And nothing has happened. I have checked the coolant for exhaust gasses, and that passed with flying colors too.

I'm going to start with the cap/coolant flush. Then watch it like a hawk to see if it's still eating coolant. Hopefully this will do it.

Thanks!

 

Get either the Motorcraft or Mishimoto coolant cap.

 

Welp, it failed. I'm loosing coolant by about 3/4 gallon per 1k miles. At this point, I think I have to start replacing things. Anyone want to take a guess where I should start? Haha. Thanks everyone for your help/suggestions!

 

Havin an issue and need confirmation of possible problem. I have a 97 F250 and was draining my efuel water separator after the truck stalled out without restarting, and has nothing but water in it. This was after changing out radiator and not being able to completely get the air out. I am leaning to injector cups!? Have no water in oil, or fuel in water, just water in my fuel?

 

in order of lowest complexity

1. cap. you did that
2. check all coolant hoses.
3. check all the coolant hose t connections...they are plastic and prone to cracking
4. check the fitting off the heater host connection at the block...there is a vent fitting there for a vent return hose...the fitting breaks.
5. put a psi guage on the cooling system and look for non linear excessive pressure
6. check coolant deguas tank for eveidense of combustion residue
7, check you oil for increase in oil level
8. check your oil for mud color
9. after the truck sits over night...slowly unscrew the oil pan drain...AND stop about 3 turns before you get to the end....if there is coolant in your pil it will drain thru the last few threads of the drain plug while the oil will not.
10. the pax side valve cover is prone to cracking.....dont know how you can evaluate this but if it cracked you will loose coolant
11. head gaskets
12. cracks in piston walls and or other block passages.


I hope you find the problem before getting to 10, 11, 12

 

Sounds like a water pump issue to me.
You are loosing coolant somewhere. Next time you park the truck place a large piece of cardboard on the ground under the radiator. The cardboard will show any leaks after a bit of time sitting.
On startup check for white smoke coming from the tail pipe. If no white smoke than it is generally not a head gasket or water jacket issue.

 

I think y'all are responding to a thread that was last updated in August 2017.

@DiverGreg probably should've created a new thread, as his issue doesn't appear to be related to the original poster of this thread back in 2017, seems to me...

 

This also should be asked in the 7.3 forum. They are great over in that sub-section @DiverGreg .

 

Thanks Joe