Need help 7.3 idi keeps running hot

DieselRon1996

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:confused:I got a 94 f350 ECLB 4x4 7.3 IDI zf5..with a (88 f250 7.3 idi in it) seems to run a lot hotter then normal my aftermarket temp gauge is reading 190-210 but the motor is obviously way hotter because I can barely touch the rad or the motor the IP also gets hot which isn’t a good thing :bail it has a new 4 core aluminum radiator motor craft water pump and thermostat and antifreeze but it starts right up when cold or once it’s hot and their is no leaks the upper radiator hose seems to collapse once and awhile while giving it gas no bubbles in the radiator or over flow no oil in the rad or antifreeze in oil but it will continue to run and seem to get hotter and hotter and it obviously gets even hotter when I drive it or give it gas :dunno:smash: the fan clutch seems to be working Could their be a air pocket in the system if so how do I get it out? I have tried many things and nothing seems to help :frustrate
 

Thewespaul

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Sounds like an air pocket issue, I would either remove the thermostat and see if that fixes the issue (Ive gotten bad motorcraft ts out of the box several times) or use an air lift system to evacuate the cooling system of air and fill with coolant.
 

DieselRon1996

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Sounds like an air pocket issue, I would either remove the thermostat and see if that fixes the issue (Ive gotten bad motorcraft ts out of the box several times) or use an air lift system to evacuate the cooling system of air and fill with coolant.


I’ll give it a try I just pulled it in my shop and that’s what I was thinking..air in the system I just draind the antifreeze out should I leave the thermostat out and put it back together to see if that was it or just replace the thermostat and then try it?
 

TurboBronco

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I'm new to deiseld but in gassers, I know bad/ improper radaitor caps can cause collapse hoses. I'm thinking under the assumption that there are no sharp bends in the hose.
 

DieselRon1996

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I'm new to deiseld but in gassers, I know bad/ improper radaitor caps can cause collapse hoses. I'm thinking under the assumption that there are no sharp bends in the hose.


Yes I did try putting my radiator cap off my 94 f450 7.3 IDIT today temporarily to see if it fixed the radiator hose from collapsing... and it looked like it did fix it...so I’ll get some of them fancy GATES ones with the pressure relief valves on them and I do remember like 2-3 weeks ago it would hold a lot of pressure in the coolest system for a long time and I could go back hours later or even a day or two after it’s cold to the touch and it would blow the cap off the radiator..but it really haven’t done it since then
 

DieselRon1996

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But i am also tempted to pull the motor and rebuild it because I can go under under the truck and spin the motor over by grabbing the flywheel/clutch by hand...and I can spin it over for awhile too like that but I think it’s time for a clutch anyway but I don’t ever remember a IDI being that easy to turn over or is it normal? but it’s odd and funny how it starts right up..doesn’t hesitate to start...and has plenty of power but like I said I am tempted to pull it and rebuild it what do y’all think?
 

TurboBronco

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As long has the cap's psi is rated for the system it should work. And yes, i second a relief valves.
Far as spinning the motor freely, I'm new to diesel, but.... no I don't think it should spin freely.
 

Slicknik

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In my experience, aluminum aftermarket radiators always run hotter , gas or diesel, doesn’t matter how many cores you have it’s about airflow.
 

Thewespaul

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In my experience, aluminum aftermarket radiators always run hotter , gas or diesel, doesn’t matter how many cores you have it’s about airflow.
Maybe if you’re buying cheap radiators, but aluminum is very efficient at heat transfer. There’s a reason why racing radiators and intercoolers are aluminum.
 

Clb

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Try burping the heater hoses during the initial purge???
also try this one...
once ya fire it up the first time after a refill, watch the gauge as it heats the stat, (i can see mine open And close ), refill as needed, once it heat spikes (air pocket time) shut it down and wait till it cools a bit(lets the statt purge back some air...remember the check ball port???) , refill repeat as needed.
I got this from a search here I think...
 

Garbage_Mechan

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One thing I have run into over the years is a blocked or missing air bleed check ball under the thermostat housing in the block. The ball should be there and free. Of clogged air gets trapped under the thermostat. If missing it allows enough coolant to bypass the thermostat to keep it from warming up unless under load. Leaving the thermostat out will cause it to overheat.
 

Slicknik

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Maybe if you’re buying cheap radiators, but aluminum is very efficient at heat transfer. There’s a reason why racing radiators and intercoolers are aluminum.


Ya cuz it’s cheap and light weight and readily available, not to mention easy to machine and form.

inconel and titanium would also work just as well as aluminum. But no one is making them cuz it it’s too expensive.
 

ISPKI

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Ya cuz it’s cheap and light weight and readily available, not to mention easy to machine and form.

inconel and titanium would also work just as well as aluminum. But no one is making them cuz it it’s too expensive.

Inconel and Titanium do not transfer heat nearly as quickly as aluminum. We use all three of these alloys extensively in my line of work with aluminum being used primarily as a heat sink for all forms of steel alloys and nickel alloys (inconel). The only other alloy we use for heat sinking is copper.

If it was a cost of material issue then we would see alot more people using austenitic stainless steels for radiators. That would at least be easier to weld than aluminum.
 

Thewespaul

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Ya cuz it’s cheap and light weight and readily available, not to mention easy to machine and form.

inconel and titanium would also work just as well as aluminum. But no one is making them cuz it it’s too expensive.
Inconel and titanium is used all the time as heat resistant parts like exhaust valves and turbine shafts, not heat transferring parts like radiators and intercoolers.
 

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