So I just bought a 6.0 with 140xxx, studded, and I'm assuming aftermarket FICM due to the fact that it's a sandyish brown color, not factory from what I understand. The problems I've had so far..
Withen 5 hours of owning it the turd wanted to get warm, as soon as the fan kicked on I took notice and watched the temp gauge. I didn't let it get into the danger zone. Dealer took it in and replaced the radiator, and it got hot again, come to find out it was just the thermostat.

BUT the truck runs fine now, OTHER than sometimes when I get on it for the first time of the day and it kind of baby hiccups at top end at about 70-85 (merging on the I5 highway) the truck sits about a week at times before driven.

Yes I let the truck warm up because I have a fancy keyless start so while I'm getting ready I let it run about 30 minutes. It only does it once or twice and that's it, and then the Tranny start to act a little dumb like not knowing when to shift. I don't have a programmer just a cold air by air raid and a commifornia "test pipe" if you will.

No check engine light or anything.

 

And is the normal temp spot. Sometimes I swear it's a smudge higher, but I just feel it's my eyes adjusting to it because I'm staring at it so long. My 6.7 work truck looks roughly the same in needle placement comparison wise, and I put the first hard as can be 22000 on it so far

 

Post some more sensor readings. Like the high pressure oil and true temps from a diagnostic reader. The gauges are only approximate and not all that accurate.

 

I'm no 6.0 expert but it's generally bad form to idle a cold modern diesel. They don't like to idle at all really. Best to get them up to temp asap. If you want a slick warm up install a webasto engine pre heater. It's a boiler that warm the coolant up to 180° in a matter of minutes.

Also, cold air intakes are not advised mod on these as the factory air supply is superior.

 

So i bought a scan guage 2. RPMs are anywhere from 680 to 720ish. Here is the scary part.... EOT gets up to 216 and coolant has a hard time getting above 205........ fffffuuuuuuuuuu******!!!!!!!!!!! And that's at 85mph going down the highway on cruise control. And fuel mileage is garbage as well. Ive also come to conclude that this truck has a harnes problem because i had a no start issue and it said that it was the CPS and in trying to find it i kind of moved some wire loom out of the way. Los story short i tried to start it again and it started and I didn't remove anything but the air cleaner box. Little did i know i was on the wrong side of the truck.

 

I thought it was a good thing if you had 216°/205° temps. 11° spread at 85 mph I'm sure it has a few rpms at that speed right?

 

I thought it meant that you had a plugged oil cooler or plugged EGR if you have a 10* difference in both temps

 

My understanding, and I'm new to all this, is that 10° would be getting up there but at a light load like 55-60 mph. 85 is considerably more load and rpms. It might be indicative that a flush and coolant job is in order though, but how many degrees is it at "normal" high speed like 65?

 

The test and threshold is 15 degrees max delta running on a flat road unloaded at 65mph. Towing, hills, excess speed, etc will likely cause it to fall outside of that range even though the cooler is fine.

 

Okay so I did more more reading. I need to go for a longer drive. I wonder if an oil change is due or will help, I've inly drive. This truck a handful of times since I bought it because I work like crazy and I don't know when the last time the oil has been changed, I might send it off to ford to get it flushed and cleaned as it is.

 

What type oil does it have?

 

If you don't know when it was last serviced then it probably would be a good idea to have a starting point for future changes. If you don't drive it much, then you have to change the oil every 5, 000 mi or 6 months whichever comes first. If it sits a lot and doesn't get hot when used, the coolant could go for about 2 years.

 

It would be nice if a moderator moved this to the 6.0 section. A lot better chance of finding out what needs to be done. Not to mention the wealth of information available in the tech folder sticky at the top of the 6.0 forum.

 

Use the scanguage II to monitor engine oil temp and engine coolant temp. Also, monitor the FICM voltage. It is supposed to run at 48 volts. 45 to 48 you won't have any issues. If the FICM goes bad, it knocks out injectors.

The EOT and ECT don't concern me. Yes, that's a bit warm. Pulling mountain grades with mine yesterday I saw those type of number. They went down when I wasn't running as hard.

The cold air intake is sometimes a cause of hiccups. Try putting the stock intake back on see how it runs.

Also, no need to idle for a half hour. I usually watch the gauges. Change the oil and filter, also change the fuel filters. Use motorcraft filters. Amazon seems to have the best on filters.