Are my temps ok or is there a problem?
 

I have a 2005 Ford F-250 with 46,000 miles. A few months ago I did a coolant flush and added a coolant bypass filter. My ECT/EOT delta is perfect staying between 5-8 def F. Since it is starting to warm up here in Colorado, I have been seeing the ECT hover around 200 F driving from work 25 miles on the highway.

I have a decent grade to get to my house and yesterday the ambient temperature was 92 F and my temperatures were ECT 210 F and EOT 215 F while climbing the long grade.

Are these temperatures withing reason considereing the ambient temperature? Or do I need to look at the thermostat or water pump or something else? Thanks!!!!

What elevation, and what's a decent grade? I ran those temps going up US 6 to Loveland Pass, but if you're down in the metro area at 6k feet and it's a 3% grade, that sounds a little too hot.

Do you have a monitor to check fan clutch lock up?

Thanks! I'm at 6,600' at the house. The last grade is probably 3 miles that climbs 800'.

I have an Edge CTS monitor but not sure how to check the fan clutch. I didn't hear the fan come on and this is the hottest the truck has gotten.

Does your a/c blow cold while stopped? That is where the fan is mist needed to pull air over the condensor to keep the a/c cold.
You should pop the hood and verify the fan is turning.
At 210 ect, you should hear the fan sounding like a jet engine. My fan will turn 1500 rpms for a moment when starting from a stop, as the sudden change in engine rpms causes the fan to go faster, at 190* with the a/c on.

The AC does blow ice cold when stopped. I will take it for a drive up a local mountain and verify if the fan is working or not.

What do you guys think?

Fan clutch
Water pump
Thermostat

It looks like my oil cooler is in good shape with a 5-8 deg F delta.

It seems like the truck gets hotter when the AC is running full blast too.

If I stay at a constant grade and the temps are 210 F ECT and 215 F EOT, and constant engine load and then the fan kicks on, how much would it lower the temps if it is 90 deg F out?

I'm not going to tell you to change hard parts without better diagnostic data. The fan clutch isn't cheap enough to swap on a hunch.

Two things you could do that don't cost money. One is set up a temporary override setup for the fan clutch. You can ground (read:GROUND, not power) a wire in the fan clutch wiring connector, and it should command the clutch to lock up 100%. If you do that, and you don't hear the fan while starting from a stop, then I would call that a positive on a failing fan clutch.
https://www.ford-trucks.com/forums/1...hich-wire.html

The second would be to wire in the high-idle mod using the BCP wire (purple/green). With my original snow plow fan clutch using this high idle would lock the fan clutch in, and I'd normally get at least one start where I could hear the fan locked in if I started driving imediately after kicking it out of high idle:
https://www.ford-trucks.com/forums/4...-switches.html

Honestly though, if you have access to an Android phone or tablet, buy the Torque Pro app for $5 and find a bluetooth OBDII adaptor, and just read the fan speed and clutch lock up PIDs. Otherwise it's still all a guess IMO.

I'm not saying it's the stat because 200* isn't unreasonable for a stock 190* stat. But since it did come after a flush, there's a chance that it could be sticking. This is going to sound odd, but 200* is actually better than the OEM stat set at 190*. Many people have changed to a Mishimoto 200* stat, it doesn't cause higher temps (past the higher base set point) because it opens fully by the same point at the stock stat, and it makes winter performance significantly better. I used to run a grill cover to keep temps above 190*, I don't bother anymore.

https://www.ford-trucks.com/forums/1...hermostat.html

I can't find the part numbers, but there was an issue with the Mishi stat fitting into some t-stat housings. I had the wrong p/n stamped on my housing, so I ordered a new housing with a stock stat in it. You could check to see if your housing is the correct p/n, if it's not order a new housing and stock stat, then you aren't out any parts costs if it's not the issue now when you put a Mishi in later before winter. Plus if we're swaping parts, a t-stat is the cheapest one short of a new degas bottle cap to start with. A cap isn't a bad idea, especially if your's is the original. The seal gets old in them. P/n for that is 9C3Z-8101-B

This is the p/n stamp on the housing. The C91 housing was the one that wasn't supposed to have problems, but either will work apparently:
https://www.ford-trucks.com/forums/1...l#post15160768

http://www.riffraffdiesel.com/degas-coolant-bottle-cap/

Awesome information! Thanks for taking the time to write this up! I will try the Bluetooth OBD app and see if it locks in. I will check back with results.

Thanks again!

Nice that you found it, can you give some background for the vehicle such as, frequency of occurrences , mileage, any other symptoms etc?
Thanks

OK. So I found out that the fan does kick on. I took it up in the mountains the other day up 285 to Conifer and I got it up to 210 ECT and 217 EOT and I was pushing it hard on purpose. I heard that fan kick on and it really brought the coolant temps down quickly.

I have 47,000 miles on it now. It seems like the ECT is 195 or so cruising and then gets to maybe 205 when I get on it. I'm going to take it up I70 this weekend and see how hot it gets. I will report back.

Since the fan is working you're probably fine then, just keep watching them and make sure it doesn't keep increasing.

FWIW The temps I have seen lately for reference on the freeway doing 70-75 mph AC on high 100+ ambient ECT 200-206 EOT 210-217. FAn speed 400-580 rpm on freeway Fan speed side streets will rise and fall from stop and go 500-1900 for a few seconds.

That is good reference. Thanks. No other issues except for a small bell housing oil drip.

Im curious to see how it does in the mountains this weekend on a very long sustained grade. I have to know how it does before I hook up a trailer and pull a Jeep to Moab!

Update!
 

Update! I put the truck to its hardest test to date with me. I left Denver and drove to Breckenridge, hauling a full tank of fuel and about 600 lbs of cargo, so basically nothing.

I pushed it pretty hard, mainly passing people going up I-70 towards the Eisenhower tunnel from Denver and the ambient temperature was about 75 F. The hottest it got was 208 F coolant and 221 F oil temp.

I could really see when the fan kicked on full blast and I was amazed how quickly it brought the temperatures down. Like, not even a minute, maybe 30 seconds and the coolant temperature started dropping in 2 deg F increments, from 208 F to 195 F. 2 degrees, boom, 2 more degrees, bam, all the while staying into the throttle. So, I think my rig is good. I appreciate everyone's help.

UPDATE