My cooling fan kicks on at 207 and is screaming at 215.

 

Thanks, Mark. I trust your advice. I think I'm going to nurse my truck along through my two trips this week this week and then see about replacing the water pump for, if no other reason, preventive maintenance. If that doesnt help lower my high end EOTs, ill go for the cooler next. Maybe by then we'll see some lower temps around here too.

I think pulling my enclosed trailer doesn't help either. Noticeable drag vs the open flatbed.

 

That's what I'm used to. But based on me manually triggering the fan to scream, which seems to indicate the fan works and has no wiring issues, without it having a noticeable effect on EOTs for more than a few seconds, I'm not sure that's the problem. Still...I wish it would scream. I guess maybe it's not operating properly at lower, non-scream speed (sorry for the technical terms, lol), But maybe it is and my bad hearing just doesnt notice. Lol Maybe a blue wire mod that turns a light on in the cab would be better.

 

I replaced my water pump, radiator, hoses, coolant with ELC and oil cooler. I went back to the factory cooler from an IPR remote (long story)and I am now finally happy with my system. When towing heavy I stay close to 15 delta in the mountains and on flat land in all outside temps.

 

And you got some steep grades in NC. That one on i-81 is a doozy.

 

I just came across this thread on this forum and have the same issues you are describing. Bismic has even been helping me there. I've been to several diesel techs with all my equipment checking out good. Did you ever solve your issue? It's like chasing a ghost.

 

If you are refering to my temps, no, they are the same and not much different towing. I am not concerned, everything is working properly and engine pulls and pulls. For some reason I am thinking there may be software issue but that is the IT guy in me.

 

That's the consensus I kind of got from bulletproof diesel. They cant find anything out of spec and say everything is doing exactly what my pcm is telling it. Pretty much last option is to have a tune written to turn on my fan sooner. Thanks for responding. How long has yours been running this way?

 

About 10 years. 2 coolers, an external cooler, radiator, flushes and ELC, still runs the same.

 

I thought I would update you on what worked for me. I was being led away from the fan clutch when 2 separate shops said mine tested good. I swapped it out with the snow plow fan clutch anyway and it's a total difference. My temps pretty much dropped 18* under the same driving conditions. I was getting up to 218-220* ECT and now I'm down to 202. All my temps have lowered across the board and even my A/C feels colder. I thought I would share with you in case it's something you havent looked into doing. I think the speed sensor in my fan clutch was off and was telling my pcm a lie. I dont know but mybtruck runs cooler now and I'm relieved.

 

 

Good info, does the fan scream? My ECTs seem to be fine, when towing in the mountains the temps went up, fan started to engage at 207, at 218 was wide open and ECT came down, oil temps followed. Normally there was a 10 degree spread, got a little higher at times especially on hard pulls. On the down grades it dropped to 202 and oil would follow, on one long grade down ECT got to 200 and oil 204. Again, it is interesting that towing and normal driving seem to generally have the same spread. Now, I did pull the Green River Gorge on I-26 the other day towing and I hit 242 oil and 230 or 232 ECT, that is a 5 mile long 6-7% grade, outside temps in the 90s but once I crested the temps dropped quickly, on the downhill the engine really cooled off, had tow/haul holding me back down the US-25 6% grade into SC.

 

I don't feel the fan screams. When I go downhill my temps drop alot lower. This all just proved my hypothesis that my fan wasnt pulling enough air. I was getting the 218-220 temps just driving home from work 70mph with no load and to see no more then 204 now is crazy. When I'm headed down hill my temps drop to 188ect and 192eot in 90s outside. If it wasnt for the damn cost of these fan clutches, I would have replaced it much sooner. I have yet to tow again with this new clutch but it has to do better then what I had before.

 

I like mine. The fan noise isn't much different, but I have not towed heavy with it yet either