Have a 2001 F150 with a 5.4, re- geared rear end to 4:11. Truck over heats when pulling steep hills and pulling trailer, trailer is just over 6000 pounds.

Radiator shop in Reno Nv said radiator was plugged up, 400 dollars later same problem. The coolant had been changed every 50k miles.

I'm down to the fan clutch and water pump, but considering electric fans with thermal switch.

When replacing the fan clutch I was told I should replace the water pump also, not sure what way to go with this problem. Stick with OEM or electric fans.

Thanks ahead for any advice.

 

I would try the fan clutch first. I seem to have more trouble with these than most. Several times over the years I have had overheating problems and the fan clutch was the ultimate culprit (after trying everything else). Everyone says they are easy to diagnose....well not for me. They can be easy to spin or hard, but I can't seem to trouble shoot them. Son's truck was running warmer than normal, swapped out the fan clutch and temps dropped right back down. That was simply running around with a/c on in the middle of the Texas summer.

P.S. Don't go cheap on this part. If $$$ is a factor, I can understand, but if possible go Motorcraft on this part. It will save you in the long run.

 

I think I'll go that route first, thanks for the response. I do believe in using OEM parts, the extra $$ are normally well spent.

 

Normally the fan has only little effect on cooling when running down the highway at 60 MPH.. Now if your in stop and go traffic, or around town at 20 MPH that's another story. ............If your temps are "close" to what you want, then it may help.. If you are really getting hot, I don't see this as a fix.

 

Ii would also pressure wash the outside of the air conditioner coil to make sure air flow can get thru to the radiator. I assume the radiator is standard size and not minimal unit ? Transmission heat also goes into the radiator to keep it cool on the hills. An external trans cooler to air can help keep it out of the radiator system.

 

Google "the myth of the electric fan" by Aaron Cake and you'll learn that your issue cannot be cured with an electric fan conversion. He explains it FAR better than I can.

It is the THERMOSTAT that controls engine temperature. If you are overheating while towing, turn overdrive OFF. Having overdrive ON means low revving on the highway, but ZERO power and massive heat buildup in the trans fluid, which flows through the bottom of the rad as well.

Also, pressure washing the a/c condenser sounds like a bad idea. Bent fins will happen unless you're VERY careful. Try hitting it with a compressor from the REAR first and see what nasties come off with 80ish psi.

 

I agree with this.
Never point a pressure washer into the grille of any vehicle for the reasons stated. Look at it first and if it is plugged up with bug guts and other debris you can use a wooden toothpick to clear out individual bugs or you can use HVAC coil cleaner like the pros use on home AC units to clean off a bunch at once. Spray it on, let it sit and make the bug guts gooey again, then simply hose it off with normal low pressure garden hose.

Not sure why OP hasn't changed the water pump.
Also, if the shop that diagnosed and swapped out a "plugged radiator" didn't flush out the whole engine/heater/cooling system thoroughly then there would still be scale and deposits inside the engine coolant passages that will migrate right back into the radiator. Back to square one, if indeed that was even a real issue.

 

Thanks for the replies. I'm well aware of not pressure washing radiators. I also have the tow package with external trans cooler. Trans runs 180 to 190 when pulling in hills. It never overheats at speed, but pulling long 6 and 7 % grades at 35 to 40 mph is when it overheats. The Sierras have some really long steep mountains and that is where I have the problem. I never use full throttle on the hills because I want to keep the trans temp down.

 

what engine speed " ? At 35 MPH you should be in 2nd gear... no overdrive.

 

At 60mph in overdrive I'm turning 2000 rpm with the 4:11 gears. Pulling the hills I'm at 3000 to 3500 at about 3/4 throttle. I have a trans temp gauge because I know excessive trans temp really shortens the life.

 

at 2800-3000 RPM with a transmission cooler you are doing everything right.. That should work... Since you say you are going 35 MPH, maybe you DONT have enough air flow to keep it cool. I still think washing off the outside of the AC coil is a good idea, and make sure nothing is blocking the air flow up front .... if all is OK, maybe a fan would help !

 

I agree with the pressure wash , just 4 inches away. pull it back so you don't bend fins an easy on the pressure , can get a lot of crap out of there,,new radiator come with new cap?

 

It has a new radiator, actually didn't need one in my opinion because it didn't change a thing.
I'm thinking it is the lack of air flow at low speed, and pulling hard. If any of you are familiar with I80 or 50 over the Sierras. The summit is 7000 ft and long hard 6% grades especially heading east. In the thin air above 5000 is when I really notice the problem and loss of power.

 

might have been worth putting a larger radiator with an extra row of tubes.... hine site it 20- 20.

 

They make two radiators, it had the heavy duty radiator, and was replaced with same.

I have had this old truck since new and absolutely love it, but is just might be time to think about a diesel, but a new truck will really drain the bank account.