OldMan

OK guys, here is my issue...
I have this 95 Ford Van E150, v8 5.0, auto (that is in Alabama.) It has a strange over heating problem that has been going on for a little while. It seems to happen whenever you are pulling the boat or if you are pushing it. Not hot rodding it, but driving it down the interstate at 80mph or so. The van will get so hot, that it will boil the fluid in the overflow. You can smell it is hot, see it's hot, and hear it's hot! I know it is not the gauge reading wrong. However, you can pull over to the side of the road while it is boiling hot and in 5 to 10 minutes, it will cool right off. You can even turn the AC on, while it is 90+ degrees out, sitting in the sun and it will cool right off.
What we have done to fix the issue....

-We have changed out the stock 2 core radiator for a new 3 core.
*- We have changed out the radiator cap.
-We have put in several new thermostats.
-We have put in new hoses.
-We have put in a new water pump.
-We have changed the anti-freeze and flushed the system. (Which is flowing nicely while the cap is off.)
-We have changed the fan.
-We have changed the fan clutch.
-We fixed the cats....
-We also recently changed the brain, as I thought maybe the computer was bad.
-We have even taken the fluid and had it analyzed to see if there was any traces of exhaust or oil in it. Just in-case the heads were lifting or a small crack in the block.
**
-Base timing is set to 10, with the spout out.
-Verified the water pump is rotating the right way.
-Verified the belt is on the right way.

As suggested, the van does an exteranl trany cooler. That cooler was by-passed for testing as well as by-passing the radiatior and just using that cooler. Neither option resolved this issue.


None of these things have resolved the problem.

At this point, I am kind of lost on where to look next. We have changed out everything that is associated with the cooling system, verified the timing, and replaced the main computer.


Any thoughts???

herrcomestrouble

which motor is it? Is it loosing any coolant? I kno you may not see it dripping anywhere...but has it been low? I dont wana sound like an ass, but have you checked the oil? Some of those have an oil cooler on the driver side of the block will go bad and cause coolant to loose pressure into the oil....If you dont have pressure, it will boil at 212* and cool down relatively quickly.....

OldMan

Cody,
I would never take it that way... I know you are just asking... and that is what I am looking for. No matter how simple it is.... I don't spend nearly the amount of time around these things as you do....

The van is a v8, 5.0.

It has never lost any coolant that we can see and we have never needed to add any.The overflow and radiator appear to stays around the same levels.

The van has had regular oil changes and we have never seen any coolant in the bucket. It has never been milky or appeared to be mixed.

If the oil cooler is bad, (I'll have him check today to see if one is there) would the pressure test on the radiator show the pressures drop? Would the oil pressure drop when it is that hot? How much of a drop would you expect to see? I am pretty sure we could hook a manual guage to it, so we would know for sure.

Tiffiny

not a van but i had a mustang that the a/c was over charged a little that caused the same problem

herrcomestrouble

No coolant/water mixing, never been low on coolant. All new parts.... lol lemme think about it i will get back to yah.

John, if it was the a/c overcharged why would it only heatup on the interstate? He said it drives fine around town...

Tiffiny

I was just giving a possibility.....

if driving around town you will not be constant on the gas pedal so if its a little overcharged it might not show up until going down the highway causing the high side to get really hot.....

herrcomestrouble

Something stupid not mentioned, radiator cap been changed? Often over looked...and causes all kinds of problems

95coBraSVT

Air bubble in the cooling system....Heater core with an air bubble in it? Just tossing it out there.

GNs-r-slow

Just a thought, inspect the lower radiator hose to be sure it still has a good spring in it and its not restictricting from suction and the cap as Cody suggested. Has the timing be adjusted or verified?

OldMan

Yes sir, sorry I will edit the original post and list that.

We thought about the lower hose collapsing too. We replace it and it still is happening.
The timing is the tricky thing that we have not messed with. I will have to get my dad to read me the exact statement under the hood. It says something along the lines of you can not change the timing on the van. You can't even see the balancer from the top of the motor, so we have NOT done that yet.


95coBraSVT - I don't think there is a bubble in the system. We ran the system open after the flush. After the therostat opened up, we topped it off. We then closed it and topped off again after it cooled back down. The levels have not dropped since.

John/Tiffiny - I will have him check the AC pressures. Anything is worth a shot...