I have read most of the forum material on this question. I am hoping for a consensus/definitive answer on this- or as near as possible.

03 w 150k miles
I installed an OEM 180 thermostat last year,
flushed, new coolant recently, bled properly.

What is the next step is getting it to run cooler? I max about 211 or so and would like to get that down.
I think I need to confirm the viscous coupling for the fan works correctly, it did the last time i checked.
There is no play in the water pump, not sure of the age, only had the truck about 18 months, 8k miles. The prev owner had the dealer do the head for $8k about 10k miles before i got it. The invoice does not list all the parts, I wonder if the WP was done at the same time?
Should I install an electric fan? The Ford unit frequently referenced?

What is the first thing you would do in an attempt to get the temp down? An inline thermostat looks pretty straight forward, but not sure exactly how that lowers temps.

HD fan coupling? Again not sure how that helps? Does it engage sooner?

Thoughts?

 

first check you VF again check your belt routing (yes they can be put on wrong) and i will guess your condenser fan is junk as it should come on at 208

 

The bypass method just lets you use a normal thermostat that opens by temperature, not pressure. Also you can get a 170 degree thermostat though I think that's too cool. Another advantage in this situation is that you could just pull the thermostat out and run it open to eliminate the thermostat as a cause for overheating. I have the bypass setup and my observations are that it keeps the temperature more consistent and takes a little longer to provide heat to the passenger cabin. Of course, thermostats are cheaper (8-10 bucks) and I can just pull the thermostat out in a pinch. The air bleed setup is better than stock and the bypass described on the forums gives you a spot for a real water temperature sensor.

I'm not sure 211 is out of line based on other threads I have read (as a maximum), especially with a 4.6. I'm with you, though... I don't want my engine that hot.

Couple of ideas.... If you are sure you don't have air in the system I would suspect the main fan, the auxiliary fan, and the radiator. You can aim a thermometer at the radiator to look for cool spots. Of course the auxiliary fan needs to come on (in the summer I couldn't get my truck over 195 even without the main fan because my auxiliary kept coming on), and last I'd just suspect the coupling in the main fan.

I switched to an electric fan for awhile and the company recommended a 75/25 mix on antifreeze for better cooling properties. Could your coolant mix be tilted the other way? Are you using dexcool or green?

Less likely things are a bum water pump, or gunked passages. I removed my original water pump at 135,000 miles and it was fine. I swapped a new one in anyway but I think they are pretty tough. I've done my head gaskets thrice and never found anything blocking water passages.

 

The electric fan conversion and the inline thermostat mod would definitely lower temps and theyre good idea for reliability's sake whether you're having issues or not. You can find links to both in the link in my description.

That said, unless your viscous fan clutch is just bad then I don't think you should be having that trouble. I'd your fan clutch is ok then I wonder if your radiator is partially clogged? Or it could be the water pump, as already mentioned.

 

So, when the engine is hot, the fan spins, almost by hand. I ordered a D1 set up from Paul and will give that ago when it shows up. I am hoping it comes off with reasonable ease.

I keep reading about an impact wrench and can only surmise people are joking. there is no way you would get one in there. What am I missing?

Question, is there harm in removing the fan now, given it probably does not work? Just so I can i am ready to install the new on?

I ordered the HD clutch from Hayden in case I need it.

No air in the system, fyi.

 

The impact system is to be used with a very long chisel, not with a socket like you are thinking. You apply pressure to the nut so that it vibrates loose going counterclockwise. Because once its broken loose you just spin it off by hand. A faulty fan still provides some needed airflow so do not remove it if you are going to be driving. Any fan is better than no fan

 

So it turns out the 40 amp fuse under the hoodwas blown. Also my #1 fusible link is failed also, what is that for?

The fan still spins pretty freely when warm, so i will probably replace it anyway.

 

You need to diagnose more. Fans have little to no impact at highway speeds, so if it runs cool on the highway but heats up in traffic its the fans. If you it runs hot on the highway it is likely a plugged radiator - you can test by turning the heater on high - if it cools off it demonstrates a lack of heat transfer through the radiator. One other test you can do - run cold water over the radiator using a water hose while idling at high temp - if it cools off then you have a radiator cooling problem.

 

A large enough sized adjustable wrench for the clutch nut whacked a few times by appropriate type of hammer will normally break the clutch loose. Easily removed mine today using large combination wrench and dead blow. If yours appears rusty some penetrating oil beforehand may help.

Using impact hammer/chisel should be a last resort method, it's not a good idea to be beating on water pump and timing cover.

......

 

Borrowed the pep Boyz tools to hold the water pump and the 36mm wrench, pretty much came right off.
Replaced the fan w a D1 from paul, the 40 amp fuse was out and the 50 amp fusible linke.

Seems to have fixed it.

Thanks for the advice.