7.3 idi coolant issues

[James Case]

hey everyone, I have been following the site for a while reading up on threads and after my last problem figured I would go ahead and seek some knowledge.
I bought a 93 f350 7.3 idi with factory turbo a few months back and have had some coolant issues. It seems to me like it’s building accessive pressure. First I was driving down the beach one day and my upper radiator hose blew and it overheated. I went and replaced the hose and it was fine for a while. A couple weeks ago I was driving home from work and the heater core pretty much exploded leaking all the coolant into the passenger floorboard. Replaced that and the next day the radiator blew out the top seam. Replaced that and also replaced the thermostat and gasket while I was right there. It was good for a few days and just now it started leaking coolant again from what seems like around the thermostat housing or in that area. I haven’t torn into it yet. A little too frustrated at the moment. There is clearly too much pressure in the system it seems. I don’t feel like fixing this just to have something else go. I need to get to the root of the problem. It has had an aftermarket transcooler system put on it so that’s not in the radiator system anymore. From what I have read the head gasket may be bad leaking engine pressure into the system. Help would be greatly appreciated.

 

[Thewespaul]

Start the engine up cold and take the radiator cap off. Let the engine warm up and once the thermostat opens you will see constant bubbling if the head gasket is blown. If you have no bubbling replace the radiator cap with a 7 psi unit

 

[James Case]

So I tried like you said, fired the truck up took off the rad cap and let it warm up. Never started bubbling but I’m quite sure the coolant is suppose to be circulating and it was just sitting still stagnant. Where it was leaking at the thermostate stoped and it starting leaking bad where the coils meet at the bottom of the new radiator.

 

[MtnHaul]

Has your degas/overflow bottle filled up during any of these unfortunate events?

Kind of sounds like your rad cap could be bad since it should release excess pressure, which obviously is not happening. Hope it's sumpin' simple and stupid like a rad cap. Good luck!

 

[austin92]

My first thought was rad cap also


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[James Case]

Overflow tank has never filled up or anything. Always stays at appropriate fill mark.

 

[Thewespaul]

Replace the radiator cap with a 7 lbs unit and see what happens

 

[YJMike92]

Two thoughts here.
First thought, could the hose to the overflow bottle be plugged completely?
Second thought, could the water pump be bad with no noticeable coolant flow with the cap off?

 

[icanfixall]

I bet the overflow hose is plugged.Mine somehow got a restriction in it.The coolant pressure would push past it but not allow coolant to be sucked back thru it when cooling down after warm up. As already posted.Bad cap or return hose is bad.

 

[Macrobb]

Two thoughts here.
First thought, could the hose to the overflow bottle be plugged completely?
Second thought, could the water pump be bad with no noticeable coolant flow with the cap off?

IDIs make so little heat that the thermostat mostly stays closed except under heavy load.
I do not expect to see coolant flowing under the radiator cap, not at idle.

 

[James Case]

I haven’t had a chance to change the radiator yet due to all the holidays but tomorrow I’m gonna go ahead and swap it out along with the gasket on the thermostat housing where it was originally leaking from. I’ll also replace the hose going to the overflow tank as well as the radiator cap. I have been debating just changing the water pump out as well. Do y’all think I should or is it gunna be an unnecessary expense?

 

[lotzagoodstuff]

Make sure you do a search on radiator caps and thermostats, lots of issues with aftermarket versus OEM on both of those parts.

 

[IDIBRONCO]

Do y’all think I should or is it gunna be an unnecessary expense?

I'm not going to offer an opinion on whether or not you should change the water pump. I will say that if you change it while the radiator is out, you'll have more room to work on it. If you do change it out, just be aware that some of the aftermarket pumps don't seem to last very long before they start leaking. I'm not sure on brands, but it seems to be varying quality control. Also, if you do change out the pump, be sure to check the sealing surfaces for burrs. I had one leak one time. It was on a 6.2 Chevy (these only seem hard to change until you do one of those) and I had to take it back off, deburr it, and then had to get a new gasket. Every time I change one out now, I'll take a flat file and run it gently across the sealing surfaces to remove any potential burrs. You can see any burrs because it will have a very shiny, lighter colored look to it. You don't need to push ******* the file, just work it back and forth until the surfaces are smooth.

 

[James Case]

I pulled everything off and just went to reseal the thermostat housing and that little ball bearing is gone. Is that necessary or can I do without it?

 

[Thewespaul]

You don’t need it