2108 2500 6.7 Cummins engine fan running a lot

[Nugnug]

The engine/coolant fan on my 2108 2500 6.7 seems to be running when it is not really needed. For instance, it runs when I start the vehicle after sitting for days. While driving it'll start running at ambient air and coolant temperatures when I would not expect it to be running at all. Not sure what's going on. No codes are thrown. Started doing this a few months ago. I was under the impression it was only supposed to come on when coolant temp hits 217 degrees. Any insight will be appreciated. TIA

 

[nlambert182]

On my 2016 3500, my fan clutch failed and my fan was always on. Replaced the clutch and it went away. Prior to the failure I did notice that it would engage more often. They're designed to fail in the "always engaged" mode.

Does it run non-stop or are there periods where it disengages?

 

[Nugnug]

It does disengage. Not running constantly .... yet. It seems to have a mind of it's own. Comes on and goes off for no reason in my opinion.
Thanks nlambert182.

 

[06 Dodge]

In my truck as soon as I turn on AC my fan will run more, being your in AZ I assume you use your AC most of the time, also if you have AGS on your truck that also effects your fan engagement if they are not fully opening...

 

[nlambert182]

Definitely get the fan checked. It may be on its way out.

BTW... AGS (active grille shutters) could be a partial culprit too but I would definitely have it checked .

 

[Nugnug]

06 Dodge. It was doing it before it got hot here, but thanks, good thought. I don't have AGS, but do have active air which I don't think is the same. I have wondered if the active air is working though.

nlambert182, thanks for telling me what AGS is. lol. I'm assuming the active air on the 2018 is NOT AGS, but I'm not positive. I'll try to find how to perform a check on the fan. Thanks again

 

[kirk35]

I had the fan on my '22 2500 replaced under warranty with 200 miles on the odometer because it was running more than I thought it should. The new fan is the same. First start of the day the fan is fully engaged until I get the speed up to around 30 mph, after that it usually engages every time I leave a stop sign or traffic light.
Last week was the hottest of the year and I never heard the fan engage. This week has been rain with much lower temps and the fan is engaging constantly. Makes no sense to me, but I'm going to let it go for a while since there are no codes.

 

[Nugnug]

Thank kirk35. Yeah, it makes no sense to me either. My fuel mileage is dropping some too. Keep me posted please. I'll do the same.

 

[nlambert182]

I re-read your initial post and it actually doesn't sound that uncommon and there may not be anything wrong with it. So try this....

With the engine cold (preferably first thing in the morning after it's sat overnight) turn the fan by hand. It should have some resistance but shouldn't be too difficult to turn. If it's extremely hard to turn then that's a decent sign that it may be giving up the ghost. These are viscous fan clutches, meaning they use silicone that flows in and out of chambers to act as the friction to engage the clutch. On mine the fluid had hardened to the point that it wasn't releasing.

When the truck sits for a while the fluid can make its way down into those chambers and engage the fan so it takes a few minutes of running and warming things up sometimes for the fluid to move back out of those chambers to release the clutch. That's why it can sometimes be running when the truck is initially started. That's actually fairly normal.

It's also going to run a lot more when the A/C is on so if you're running the A/C at full blast with these hot temps the fan is going to run more often than not. It's also going to run more if you're putting around town since you aren't pulling as much cool air across the radiator. The fan works off multiple temp sensors, not just the thermostat.

 

[Nugnug]

hi nlambert182. Thanks for the extra information! I'll try what you suggested. The heat here has adverse affects on everything with any moisture content for sure. Horrible on batteries, tires, plastic ..... so, fluid in the fan clutch is most likely going to be affected in some way.

I'll get back to you with my findings. Thanks again!

 

[68PowerWagon]

Mine is doing it now to. Only 7,000 miles on the clock. No way this is normal! Runs just as hard at 188* as it does at 200*. It gets REALLY annoying when I pull my 5th wheel as I am in the 2-2.5k engine rpm range a lot. A weird coincidence is that I started noticing it more after I had the Banks Ram Intake installed. My luck the dealer is going to say... oh yeah that's your problem. Even know there are thousands of others who have similar mods. If I wanted to hear an engine run this loud, I would have kept my 6.4 Hemi!

 

[06 Dodge]

Mine is doing it now to. Only 7,000 miles on the clock. No way this is normal! Runs just as hard at 188* as it does at 200*. It gets REALLY annoying when I pull my 5th wheel as I am in the 2-2.5k engine rpm range a lot. A weird coincidence is that I started noticing it more after I had the Banks Ram Intake installed. My luck the dealer is going to say... oh yeah that's your problem. Even know there are thousands of others who have similar mods. If I wanted to hear an engine run this loud, I would have kept my 6.4 Hemi!

I have been told the climate control/AC/heat can call for the engine fan to engage even if you/we don't think it's needed, also check to be sure your grill shutters are working...

 

[Nugnug]

Sorry to hear 68PowerWagon. I haven't been able to drive or do any more evaluations on mine in weeks. It's just way too hot to be outside for more than a few minutes here. I'll get back to it as soon as I can and give you guys an update.

 

[68PowerWagon]

I have been told the climate control/AC/heat can call for the engine fan to engage even if you/we don't think it's needed, also check to be sure your grill shutters are working...

Yeah I have shut the AC off for 15-20minutes & it didn't seem to help it at all. I will check the next time I drive it to see if the shutters are open. Fairly certain they are, but I wanna be 100% sure.

 

[Nugnug]

Yeah I have shut the AC off for 15-20minutes & it didn't seem to help it at all. I will check the next time I drive it to see if the shutters are open. Fairly certain they are, but I wanna be 100% sure.

I've never seen the Active Air door open to the grill of my truck. I have no idea if the Active Air is working or not. I don't have the grill shutters, just a small round "door" at the air box to the grill, and another to the passenger fender.

 

[nlambert182]

I think that only opens under acceleration.

 

[crash68]

I've never seen the Active Air door open to the grill of my truck.

A description of what it does:

The Ram Active Air box is a dual-inlet type diesel air filter box with the ability to vary the source of incoming air. In normal driving conditions, air is drawn from a protected source under the hood. As under-hood temperatures rise, the Ram Active Air filter box switches to a system drawing air from directly behind the truck's front grille. Ram developed this system to combat power loss in hot, dry, up-hill conditions when temperatures under the hood have been shown to climb to extreme levels.

During testing K&N determined the engine performs better with the Active Air system than removing it.

 

[Nugnug]

Thanks guys!

 

[06 Dodge]

Yeah I have shut the AC off for 15-20minutes & it didn't seem to help it at all. I will check the next time I drive it to see if the shutters are open. Fairly certain they are, but I wanna be 100% sure.

I see you have a Laramie did it come with climate control to where you set the temp where you want it and it keeps it at the set temp? If so Climate control can turn on & off AC without you touching any switches... I think I recall reading there are 3 different sensors can can call for the fan to engage...

 

[Nugnug]

@nlamber182, It was finally under 100 degrees this am, so I got out there and checked my fan spin resistance as you suggested. It has some resistance, but it spins without too much pressure. I had spun it when it was new, and it does not seem any different now.

Thanks for the suggestion, and sorry it took my heat intolerant butt so long to do it.