I have an '05 FX4 screw, 5.4 with 3.73 gears. I tow a big bass boat quite a bit. I am thinking of changing out the stock thermostat to a 180 degree stat to get this thing to run cooler for the hot summer months here in Oklahoma.
I am not saying the engine is running hot now but would prefer not to worry.
Pulling a big azz boat, running the A/C and cruising 75 mph when it's 98 outside does make me pucker as the temp guage needle now sets a tad below the 1/2 mark.

Does anyone know what the stock stat is?

Has anyone ever done this? Is there any draw back or problems it would create?

Any recomendations will be appreciated..

Thanks

 

i don't know if this will do anything.
i was always under the impression that the thermostat temp rating was when it opens up. once its open... its open. no difference. at least that's the prevailing thought on the chevelle/elcamino website forum i visit.

oaw

 

It can be and has been done. I believe the stocker is a 190 degree thermostat. You might want to look into efans, help with the cooling, A/C and power, just a bit more money. Check out Flex-A-Lites site for info on both the fans and thermostats. I am waiting to install mine, just need to find the time. Best of luck.

 

I think that your factory stat is 192 degrees. But the difference would be that your thermostat would open up at 180 instead of 192, and tend sto stay cooler. Just stays at a lower temp because it opens up the thermostat earlier so it doesnt have tim to heat up to 192. I have also heard that these motors are designed to run at about 190 degrees, so maybe you should get a temp gauge to see if the dummy gauge is lying to you or not. I usually run at about 195-200 degrees at 80 mph on the highway with no load behind me based on the edge, so I wouldnt think the gauge is lying to you but you never know. If that makes any sense.

 

With over 50 dyno pulls on my '04 5.4 4x4 Screw, we have discovered that it makes optimum power right at 200-205 degrees. Therefore I have my electric fans set at 203 and 213 degrees..stock thermostat is a 192...

 

Hi.

Leave the stock stat in for best power. Put in some Redline Water Wetter.

Install e-fans.

Change up to synthetic tranny fluid and change it regularly.

Install an active tranny cooler - it's the tranny temp I'd be worrying about.

Here's a good one:

http://www.troyerperformance.com/cgi...gno=PPI-ATCKIT

Cheers
Grog

 

Thermostats are not precession devices, sadly.
About a 2% variance is normal. 5% is not rare in aftermarket units.

Why this is important is because much of your engine controls are temperature regulated.

Example your lock torque converter may or may not engage at low temps. Ditto the emissions equipment. This roughly means your system may run richer and get worse mileage at lower temperatures. So if you put in a 180, and it tends to open fully by 175 (very normal) you might experience transmission difficulties, poor mileage, etc.

I have personally experienced failure of converters to lock on two vehicles that I lowered the thermostat to below the expected level. I lowered the thermostats to make more horsepower on non-emissions engines. Tampering with the thermostat is of course against any local emissions laws. Which may or may not matter where you live.

Once a thermostat is open, it is open. If your truck is running over 192 the thermostat is out of the loop.

What you tend to get is a engine that gets worse emissions, poorer gas mileage, less heater, but still overheats when over loaded.

If the truck runs below 212 degrees it is normal.
If it runs between 212-232 you may have an overload problem. And fixing it will not be as simple as swapping a thermostat. The thermostat will make no difference over 192.

Heat was a big problem in engines when the oil broke down at these temperatures. That was a long time ago...

Aftermarket thermostats tend to be pretty poor quality. Even the top name brand used to come back across the counter more than I would have liked...
So if you must, get a top quality one. That puppy sticks one time and you are out an engine, and it will NOT be under warranty.
Chris

 

I say don't mess with it. I've towed a 5x8 U-Haul and a bed full of stuff to and from Texas, approximately 900 miles one way, with stock everything in the cooling system with no problems. And that was hauling *** the whole way, 80 mph or so, with a lot of forced 4-3 downshifts. Your stock cooling system is more than capable of keeping your engine temp in check. If anything while towing in the summer, transmission temperature is something to be more concerned about than engine temp.

 

I wouldn't worry about it. I live in Tulsa and I tow my 85 Toyota all over the place to go off roading. My total weight is around 6000lbs. I have never had any problems with cooling no matter what the temp from 20 to 105 degrees F.

 

Like MGD fan said, I would put a tranny cooler on it, thats where you are going to get your heat when towing. And try the water wetter if you really are concerned with the coolant temps, cause it really does work.

 

On the water wetter stuff do you just top off the radiator with it or dump it in the overflow tank.

 

Hi.

Here's some more info - the usage directions are near the bottom ....

http://www.racerpartswholesale.com/redtech3.htm

Cheers
Grog

 

Thanks to all for the feedback.

The truck does have a factory tranny cooler that comes with the towing package so I feel OK that part is covered.

Currently the engine does not appear to run hot. Just thought cooler is better. But from most replies that is not the case.

What is the best way to check the temperature besides installing a seperate guage? Stick a thermometer up the tail pipe?

Thanks again.

 

Yes there is a trick to readin the coolant temps, and actually anything you want on your truck such as rpm's, speed, voltage, oil pressure, you name it. At least on my XLT clucter this is what you can do. Put the key in the ignition, press and hold the tripometer button, turn the key to the "on" position without starting, when the odometer says "test" let go of the tripometer and the gauges will flicker and then sweep. Then you can keep pressing the tripometer button until you come across "C temperature" and it will have a readout of the temperature, but this may be in degrees celcius, not positive. I have not compared this to the edge reading yet, which are in Degrees F. This is the way you can read DTC codes also. Hope that helps.

 

For what it's worth, I think that it would be a waste of time. One of Ford's main proving facilities is in Arizona, the truck was designed to work in HOT temperatures. I have pulled a ~7000lb trailer from Dallas to Little Rock with the ambient temps 95+ with no cooling issues. Also, your truck has a "fail-safe" cooling system. If the truck starts to get too hot it cuts the spark to a cylinder at a time to cool the engine. A colder t-stat would only confuse the PCM.

Joe