air lock in cooling system?

[Knuckledragger]

After verifying the temps with an accurate gauge, I would find out for sure that the water pump is actually circulating coolant. These trucks have the radiator cap taller than the rest of the cooling system, air should naturally come out without any special fussing around. Extra heating is usually a result of a blockage or no circulation. If you have a 7.3, you may be feeling the early effects of cavitation, which will heat up the coolant in a hurry. Check for coolant in the oil.

 

[Sweanpup]

Ian the cooling system like instantly preasurized upon starting the truck by chance? Or once it's filled and the radiator cap is off while running is there a constant stream
Of air bubbles you can see in the radiator?

when its running and the cap is off theres not s steady stream of bubbles but every 20 or 30 seconds ill get a big one.

You mentioned it goes to the "red" in a short amount of time, are you relying on the factory temp gauge? If so that's probably your issue. Get a real temp gauge and see what your temperatures are.

it doesnt instantly go to red but it consistantly gets warmer and warmer. i know the stock temp gauge is a joke but the truck used to never go above R or M and now it does.

 

[Thewespaul]

Don't let that gauge bother you at all, that sensor could have been bumped or gotten a little wet and that would make your change right there.

 

[Sweanpup]

ill pick up a real gauge here shortly. it seems to be functioning as normal. i can only drive it maybe a mile before it starts getting real hot almost as if the Tstat isnt opening. im ordering another motorcraft tstat and ill mess with the ball in the upper tstat housing as well. also im running the fleet charge coolant (red/pink) should i flush it all and replace with a different coolant?

 

[Thatoneguy]

Have you tried just running without a T-Stat? Just pull it out and put the upper radiator hose back one with a good seal and gasket as if the t-stat was in... That will tell you if the t-stat is bad or not before going out and buying one.

 

[Thatoneguy]

And i would only replace if your coolant actually needs it... If you have gunk in there, strange colors, or can see crap on the fins that shouldnt be there, then yes... If not then thats not your issue. Are you running a coolant filter?

 

[Sweanpup]

i am not. the radiator and the coolant are brand new. im startring to think the radiator could be clogged? ill try pulling the Tstat and going from there.

 

[Thatoneguy]

Ya that's what I would check if after pulling the tstat the issue didn't resolve...

 

[pelky350]

if possible you could try pressure testing the system to see if there is any leaks. With the little pump and guage pressure tester. Try seeing if the system like instantly pressures up when you start it with cap on still. From a point where there is no pressure before starting. It is possiby the actors guage is not working correctly up in the red zone is pretty dang hot(typically) but I don't know the exact temp it goes to red at

 

[franklin2]

i am not. the radiator and the coolant are brand new. im startring to think the radiator could be clogged? ill try pulling the Tstat and going from there.

Stop and think about it a little bit. You said it was fine before you worked on it. So the radiator should be good correct? You tested the thermostat, it worked ok correct?

Does it get hot just sitting there idling? If so, I don't think it would be the fan. I may have missed it, but have you sat there with the radiator cap off, and waited till the thermostat opened and can see coolant flowing by in the open radiator?

With the thermostat shut, it's natural for the top end of the engine to get air locked. It doesn't matter if the radiator cap is the highest point in the system, the air can't get out if the thermostat is shut. You can try one of the previous methods to help get the air out, or hang in there and let it get hot till the thermostat opens. There will be a large delay, there is usually no water, just air and steam hitting the thermostat, so that is what causes the delay before it opens the first time if there is air in the engine.

 

[OLDBULL8]

In the t'stat neck there is a check ball, that ball must move freely, shake the neck and it should rattle, make sure the small hole in the t'stat gasket is open. That ball passage is open to the radiator to expel block air and any air around the t'stat until coolant hits it, then it will seal off causing the coolant to surround the t'stat.
Make sure the radiator bottom hose is not collapsing, engine running. There should be a spring in it to prevent that.

You must be registered for see images attach

You must be registered for see images attach

 

[snicklas]

I agree with franklin.... keep an eye on it, but let it warm up.... My 92 still only has the factory gauge.... (yes I know......) but when we replaced the radiator, the first start, the factory gauge got all the way to "L" before the thermostat opened...... after that first time, it stays in the "O-R" range.......... it will freak you out the first time.......

 

[Why Me?]

i am not. the radiator and the coolant are bd new. im startring to think the radiator could be clogged? ill try pulling the Tstat and going from there.

I once left all the packing peanuts in a muffler and instaled it...couldnt figure out what was wrong untill it suddenly blew and started snowing peanuts

 

[Sweanpup]

thank you guys for all of the responses! it ended up being that new radiator. it was clogged 90% and the coolant was barely flowing through. I should've checked it before i put it in. I pulled it out and slapped in my old one and acid flushed it and its never ran cooler lol.

 

[FORDF250HDXLT]

my radiator was full of gunk so i replaced it with an aluminum spectra radiator

it ended up being that new radiator. it was clogged 90% and the coolant was barely flowing through.

Swell.

Replaced the rad.