I've been driving around town and noticed that my fan has been coming on when I stop at a light but then turns off as I come up to speed...normally I wouldn't think anything of it, but I also noticed that it will just randomly turn on even when driving. My coolant temp is in the middle and does not vary at all whether driving or stopped. I do not recall this on my old 6.0L but it was a year older. Is this normal or am I witnessing impending doom? I love my 6.0L I want it to last me a long time!

 

Buy a gauge to read live data. Scangauge2 has been advertised somewhere on here for $112.
Is there coolant in your degas bottle?
When was your last coolant flush?

 

I am the new owner and will check the coolant level tomorrow as I didn't have time today. This is a new to me truck so I have to take it down to the local Ford diesel tech to see if it needs that...is there a way for me to tell? I spoke with the precious owner and all maintenance was recently updated. Fuel filters and all. Its just weird that the temp stays stable yet the fan cycles randomly. I should have my live scan tool by the weekend.

 

If your running the AC at the time, the fan will come on. Then around 45mph, shut off.

 

The gauge is what doesn't indicate when the fan will be activated, there are a number of inputs and the PCM decides when to increase fan speed. Your fan is totally variable and computer controlled. Yes there could be a problem, but a working fan is a good thing. I put fan speed as one of my monitored gauges and once you have that, you will not beleive how often the PCM adjusts it -- you only really hear it like over 1000 rpm, under that maybe a whirrr sound.

Get hooked up to some data collection -- I'd go Dashboss or Torque because they are so way more powerful and easy to use than scangauge, but there are so many folks here that are used to what was innovative at one time, that it's like discussing religion or politics. Good news is there are experts here on most all data collection/display devices. You just need to pick one and then start seeing what is really going on under the hood...

 

I run my A/C all the time brother...I am a native Floridian, so I enjoy the heat for the most part but it gets hot as a **** here. I will pay more attention tomorrow and my obd scanner should be here in a few days and I have Torque ready to go. It is only coming on at low speed for the most part though. That I am sure of.

 

OK, so had a chance to take a look and there is no fluid in my overflow/degas bottle. Trouble! So I need to fill it asap on the way home today. What fluid is best?

 

Filled it up and radiator is leaking everywhere...haven't had a chance to get a good look. f******;ck!!!!

 

Is it the radiator or degas bottle that is leaking? Also how full did you fill the degas bottle? Never fill it above the low mark that is molded into the degas bottle, low is the new high. And what coolant did you use?

 

Don't mix coolants. I would consider flushing and get some fresh coolant in it.

 

Its leaking from the radiator somewhere...can't see it cause of the shroud and fan but its dripping all along the bottom and from the bottom of the shroud. How bad is a radiator swap on these? I'm pretty handy just never worked on diesel stuff. Delaership wants $730+ for a radiator swap.

I used 50/50 to too it off.

 

What's weird is it never once overheated! I drive it 100+ mikes the other night and been driving to work daily. Just noticed the fan was randomly running. Glad I'm **** about gauges and noises.

 

Should I drive it the 15 mikes home or have it towed? It hasn't overheated but now I'm gun shy.

 

I did fill it to the top line, but it kept taking fluid so I kept filling. Does it have a purge somewhere if its overfilled? Maybe hopefully that's what's blasting fluid?!?

 

Here is a video on changing out a radiator:

Edit, this one is better: