I have replaced my thermostat, backed the fluid back to 50/50, and my 92 7.3 idi is still running at 230. I checked the fan, waterpump seems fine, radiator is clean, but my main question is should the system be building pressure in the hoses?

 

It should have some pressure but the radiator cap should pop at 14 psi IIRC. If your water pump is going out it might get hot too and make more pressure than normal

 

If thhe waterpump was going out wouldn't it leak from the weep hole though? Mine is not leaking anywhere

 

Normal pressure is 13 to 16 lbs depending on your radiator cap and who you ask. I run 13lb caps on both my trucks. When you say your radiator is clean, what does that mean? You can't see down inside of it. Did you feel both hoses as I suggested? This pressure you are describing, is it equal in both top and bottom hoses? Are both hoses the same temp? If you are running hot under normal load and doing so quickly, your fan clutch is not your problem. I am not saying it is o.k. but it is made to dissipate excessive heat from your radiator when your engine is working hard. It doesn't seem like you are even working her hard before she starts to heat up to me. If your water pump is turning and not leaking, that is not your problem. It is not hard to do a cooling system pressure test. Some auto parts stores lend the test equipment. My guess though is that your radiator is tired and restricted. You could rig some sort of flow test pretty easily by taking off the hoses and monitoring how much water flows from the inlet to the outlet and at what rate, but you would need a baseline to know if you are getting good flow or not. One thing I can tell you is that I replaced both radiators in my trucks, and they both run as cool as can be now. A Champion aluminum radiator is about 230 bucks, and after you scrap the old one (the last time I did I got 75 bucks for it) you are out 150 bucks and sure of where you stand.

Did you use a motorcraft t-stat? Did you test it before you installed it? That is the only other thing I can think of that would cause your problem, short of internal engine problems.

Mac.

 

No the water pump will only leak if the seal goes out. The impeller could be worn and not circulating water.

 

Ibought a motorcraft from the Ford dealership here in Jacksonville FL, it is currently in the 70s, my truck is under no load, And in 10 miles it'll get to 230. The hoses I did check like you suggusted macgyver, thelower was cooler, but now they both are the same temp and same hardness. I've spent a lot of money on this truck, so any cheap test, or free tests are best for me

 

if it heats up that fast it sounds like water pump to me, even if the radiator were only working poorly that is fast.. sounds like the t-stat is not opening or the water pump is not circulating.

 

Dixie,

I read through your other thread a while ago. It is highly unlikely that you got a bad t-stat from Ford, but possible. Did you test it? the next question, is where are you getting your temp numbers, since you are quoting numbers, I imagine you have an aftermarket gauge, What brand? a Radiator flow test would be easy to rig, and cheap if not free to do, but as I said, you would need a baseline, or known clean clear radiator to test to get an idea of what should be expected. I am down with the whole "spent a lot of money on this truck" concept. All I can see causing your problem is either the t-stat or radiator. It is true that the vanes on the pump could be warn and not pushing much water, but that would be surprising without any other evident wear or damage and no leaks.

 

Not to say youre wrong Mac but my 92 waterpump went, and after changing everything else in the system I changed the water pump (that didnt leak a drop from the weep hole, so I thought it was good to go) it fixed the overheating issue. Mine would do the same exact same thing 10 min of light driving or standing on it on it, it was hot and I had to pull over and let it cool down. I finally decided this after getting a new radiator, fan clutch, 2 thermostats (motorcraft) I took out the thermostat all together, the hoses were new, I even changed the heater core (unrelated problem). It still got hot, so the water pump was literaly the last possible thing it could be but I spent a lot of money guessing at this problem. You could be right about a clogged radiator but my thinking, after my last cooling system adventure, is that water pumps are about $110 and radiators are about $250-$350.

 

Oh and BTW if you do change the waterpump dont use a dead blow to break the gasket... I had to take the entire timing cover off to fix the gasket I f'ed up.

 

IDIguy,

I never said it wasn't his water pump, just that it would be highly unlikely that the vanes would wear without any other tell tale damage. It is true that a WP is much cheaper than a radiator, in fact, Rock auto has this one for 38 bucks. He could try to change it out and see if it helps if finances are an issue.

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I have had to replace both of my trucks radiators, and both my trucks water pumps, so I can't say either way. Remember though your old radiator is worth about 75 bucks in copper, if you scrap it right, so your net is about 150 on a new radiator.

 

OK good advice from everyone! It all ending when I swapped out the radiator with. The one I had at my shop. Now it runs 190-200°. Thank God cause next I was gonna switch from clutch fan to a dual electric fan hookup. Still may think about that though, any ideas?