Intercooled, now having heat issues

[nightrunner84]

Ok, I added a intercooler from a 99 7.3, and fitted a condenser from Crown Vic to the front of a 92 F350, Turbo-ed 7.3. It was 92 degrees today, and the temp gauge went past the L of the Normal range. It started puking coolant at a store we stopped at, and I added 1 gallon to make it full again after cooling down a bit. The radiator cap was bleeding off pressure, so was replaced with 15psi cap. Now, it's no longer puking coolant, but runs hotter than I'd like. Temp gun says 224F at the hottest point I could find on the upper hose outlet on the engine.

If it can't stay below 224F just driving around with the air on, I've got no chance at pulling my fifth wheel in the heat.

I've seen mentioned here, upgraded radiators, and other upgrades to get these engines cooler. With the radiator "covered up" by the new intercooler and the much larger condenser, what can be done to get it cooler and ready to tow. Am I screwed?

The intercooler, radiator, and condenser fins are clean and unobstructed.

 

[chillman88]

Are you certain your fan clutch is working properly?

 

[nightrunner84]

Are you certain your fan clutch is working properly?

It feels pretty tight when it's hot. Would a slipping clutch fan matter at highway speed?

 

[IDIBRONCO]

Are you certain your fan clutch is working properly?

Good question. Mine is when it started puking coolant, did you leave it running or shut the engine off? If you left it running, that could be normal. There isn't as much air flow with the truck not moving and the fan turning slower than it is at road speeds. Another thing is that I'm sure you were checking temps with the truck idling. You could see higher temperatures in this condition.

 

[IDIBRONCO]

It feels pretty tight when it's hot. Would a slipping clutch fan matter at highway speed?

Yes it could make all the difference.

 

[nightrunner84]

Good question. Mine is when it started puking coolant, did you leave it running or shut the engine off? If you left it running, that could be normal. There isn't as much air flow with the truck not moving and the fan turning slower than it is at road speeds. Another thing is that I'm sure you were checking temps with the truck idling. You could see higher temperatures in this condition.

The truck was off when it was puking, but I think that was from the old cap. The new one actually holds pressure. I was checking the temp with the truck idling, but it was a few seconds after pulling off the road.

 

[nightrunner84]

Yes it could make all the difference.

Would it hurt anything to direct couple the fan to the pulley, removing the clutch entirely?

 

[nightrunner84]

Is there a more efficient radiator that's not junk? I've seen a few mentioned here, but they seem hit or miss.

 

[IDIBRONCO]

The truck was off when it was puking, but I think that was from the old cap. The new one actually holds pressure. I was checking the temp with the truck idling, but it was a few seconds after pulling off the road.

I'll bet that you're right about the cap.

Would it hurt anything to direct couple the fan to the pulley, removing the clutch entirely?

I think this would be a good idea. That way you'll know that the fan is turning fast enough.

 

[The_Josh_Bear]

My two cents on the cooling issues:

1. What's your IP timing at? If you're overheating unloaded it could be retarded.

1a. @IDIBRONCO makes a great point that idling with a poor fan clutch could be the issue. If the fan is never engaging at idle it *will* overheat. Happened to me! I had a bad clutch for a long time and yes you need them on the freeway/highway at times. Though unloaded not likely. If you never hear your fan roar when you first start the pickup, clutch is toast. You can modify them by drilling into the housing and adding more silicone fluid, search for that if you're a fixer. I almost did this but went E-fans instead. I should have just fixed the clutch.

1c. Making your clutch static will hurt nothing but your fuel economy. And you'll have ice-cold A/C at idle speed to boot!

2. It is possible the T-stat is only opening partially. Happened to me.

3. Since youve got the heat gun out, take a hot temp of upper hose and lower hose. See what the difference is. If

4. The radiator cap is a concern but a properly working cooling system unloaded shouldn't even need the pressure. Also many of us switch down to a 7psi cap to keep things like from leaking as easily. Seems to work well.

5. The 7.3 had factory block-off plugs in the heads. These restrict flow intentionally to increase cylinder temps for emissions. Search "IDI 7.3 coolant mod" in the Google machine for lots of good info. You can't change it without pulling the heads but it's good to know anyway and gives you something to blame.

Happy wrenching!
-Joshua

 

[IDIBRONCO]

2. It is possible the T-stat is only opening partially. Happened to me.

Another good possibility that I didn't think of. It happened to me too. It was in a 1984 Mustang. I had pulled out the CFI 3.8 and installed a 302 with a carb. I put a new thermostat in it when I did the swap. It was stuck closed. I put another one in. That one was stuck partially open. I could drive around town and be fine, but when I tried to go down the highway, it would get hot. I finally tried to push it too far and it cost me an upper radiator hose. That's when I put the third new thermostat in and that one FINALLY worked right. This all happened in the late fall when the daytime temps got up to the 50's or low 60's.

 

[nightrunner84]

Another good possibility that I didn't think of. It happened to me too. It was in a 1984 Mustang. I had pulled out the CFI 3.8 and installed a 302 with a carb. I put a new thermostat in it when I did the swap. It was stuck closed. I put another one in. That one was stuck partially open. I could drive around town and be fine, but when I tried to go down the highway, it would get hot. I finally tried to push it too far and it cost me an upper radiator hose. That's when I put the third new thermostat in and that one FINALLY worked right. This all happened in the late fall when the daytime temps got up to the 50's or low 60's.

There wasn't a problem until I put the giant intercooler, and giant condenser in. I think they're blocking a lot of air flow. The problem doesn't appear until the low 90's. I think I'll try to pump grease into the clutch fan, like a read someone did here. That, or make some tabs to keep it locked up. I'll report back what I find, but it'll be later this weekend.

 

[IDIBRONCO]

When I do a build, if there's a fan clutch issue, I know that I'm just going to lock mine. That way I won't have to worry about it.

 

[CBRF3]

I put a plug behind ( believe is 3/4 inch freeze plug ) the Thermostat for the recirc to the water pump and remove the check ball in the thermostat housing and use only motorcraft / international thermostats. The plug in the back of the thermostat area you want to put in as far back as you can so the thermostat can still fully open I have found that recirc port can cause thermal runaway when your doing hard towing in hot temperatures and how I came up with this mod. This mod doesn't effect your time to warm the motor up to operating temps in the winter because the thermostat is still controlling the flow to the rad and also this forces more flow thru the heater core at idle meaning if are in cold climates idling your heater will put out more heat.


I also want to point out in a overheat situation where coolant is boiling the recirc port would just vapor lock the coolant flow in the pump and heads and cause the entire cooling system to go in thermal runaway as I said before. The plug behind thermostat fixes this meaning nothing but coolant will enter the water pump from bottom cold side of radiator unless the rad is bone dry of coolant .

This mod has saved me a few motors over the years going thru the mountains hauling heavy loads and drops your oil temps also as the coolant entering the water pump is 90% fresh cooled coolant from the bottom of rad instead of recirculated near boiling coolant.

I had a truck that was hitting 240f oil temps before the mod did the mod oil temps in same temperature same load and everything on same mountain dropped to 215f-225f that is a big drop and my coolant temps dropped 15f-20f after the mod that is when i really started doing it to every one of these engines I had.

 

[Booyah45828]

Doing that would make the heater circuit the only source for coolant recirc with the thermostat closed. Not sure if I'd like that. The water pump, even though it isn't positive displacement, can create some good head pressure internal to the engine. That pressure would only get bigger if you're using a ranger bypass valve in your heater hoses.

By design, the thermostat should plug that hole nearly off when the thermostat is open.

Can't really argue with your results though.