'95 F150 5.0 2wd

I know the first thing everyone is probably going to say is the fan clutch. There's not fan clutch, I have a '95 Thunderbird fan on it with a Flex a lite controller. I've also had 3 different fans on it. 1st was a Taurus fan mounted inside the stock fan shroud, 2nd, was a T Bird fan with the Ford F4SH-8k621 motor in it, 3rd was a T Bird fan with a Siemens PM9027 motor in it which is supposed to be more powerful than the F4SH motor, both of those were mounted directly to the radiator.

A little info. New ac compressor, new drier, new (RED) orifice tube. Reman 5.0 long block with about 4k miles on it. New water pump, new thermostat, new radiator. Now, outside temps have been in the upper 90's lately so it's been worse than it was but it's been an issue for a while.

When running down the highway with the ac on all is fine if I keep the rpms under 2k. If I run it hard to pass or speed up the engine temp starts to creep up. I hit it for a few seconds and the gauge creeps up a little and stops, but stays there. Then if I hit it again it will creep up a little more, then stay there. It never drops back down. The fan is constantly running on high speed. If I turn off the ac the temp will still hold at wherever it's at with the fan still running. The temp will drop if I come to a stop and sit for a few minutes.

If I don't turn on the ac at all I can run the truck hard and it won't get too hot. But the fan will still come on.

Another piece if info, the high side line on the ac gets extremely hot.

So I'm thinking that this could be a combination of issues. Ac high side getting too hot causing the air coming to the radiator to be much hotter than normal, the fan isn't pulling enough air, possibly a blockage somewhere in the ac, possible blockage in the cooling system, etc.

I have my thoughts on where to start but wanted to get others opinions on this that might bring to light something I haven't thought of yet.

 

Fan clutch. You don't have one.

I've tried electric fans on various vehicles. None of them ever worked as well as the stock fan.

 

Where the stock fan sits in relation to the shroud is important because it creates a vacuum across the radiator. That being said I use a 90's mustang non ac fan clutch and the plastic mustang fan. Temps are mid nineties, can't even tell when the fan clutch is locked from sound or engine drag. Total cost around $60.
E fans have to be set up just right to work properly, the mustang fan setup gets rid of the heavy duty clutch setup with way less hassle.
If you still have a known good clutch and fan throw it on, this would tell you if the problem is your Efan setup or something else. I swear it seems like the mustang fan works better than the factory fan and clutch.

 

I've been looking for the stock fan & clutch. They're in the garage somewhere. I was going to throw them on when I found them to see if it acts different.

 

check the lower radiator hose and make sure it has the spring in it so it doesnt collapse under the water pumps suction created at higher rpm....


if the spring is there then the radiator isnt big enough to handle the load. you may have gotten a light duty radiator when you should have gotten the Heavy-Duty AC unit... there are light duty AC units as well. Make sure the lower Air Dams are in place too... they direct air to the rad and without them can actually pull air from the rad going down the road.

 

The spring is in the lower hose. It's not collapsing As far as I can tell I didn't get the light duty radiator. It's almost 3 inches thck and looks exactly like the oem on that I pulled out. At this point I'm contemplating having the oem radiator cleaned and the pinhole it has patched. All air dams are in place, the front bumper and lower dam are less than a year old.

 

I'm curious if you're using the stock dummy gauge our an aftermarket one? Have you verified it's actually overheating with an inferred heat gauge?

 

Do all air dams in place include the fan shroud?

 

No, the stock fan shroud is off and the T Bird fan is mounted directly to the radiator.

 

With no shrouds the fan only cools the part of the radiator it sits in front of.