HELP...2010 cooling fan clutch problem again this year!!!

[KOwens]

I made my annual trip to northern AZ from SoCal this past week...and upon returning pulling up the Ocotillo grade with the outside temperature hovering at 109 degrees...my engine cooling fan clutch would not engage! Coolant temp quickly ramped up to 245 degrees and gave me the EVIC "red thermometer" icon and chimed...so I slowed down and got it under control...very slowly without any fan spool up, unfortunately.

Last year at almost exactly the same date, I experienced the same problem...took my truck to the dealer (I have an extended warranty) and they replaced the ecm bird-brain with a "refurbished ecm" and told me they solved the problem. Evidently not...and now I have a refurbished ecm for my trouble. Other than this one trip every year, I don't tow anywhere else at these extreme temperatures...mostly tow in the fall/winter months...so it took a year to recreate the problem.

Can any of you TDR gurus tell me what is going on with this ecm-controlled fan clutch...and what is going wrong with mine...so I can tell my ignorant dealer service writer what needs to be done to solve my cooling problem before I ruin my truck.

I have the CD version of the repair manual...and I can't find anything useful in its contents to help me troubleshoot the problem myself. Worthless compared to my 1995 repair manual that was a printed manual. If the info is on this CD, I can't find it.

Anyway, I need to tow my trailer back to AZ again next week and will be returning about a week after that...and without a fix I'm going to have a rough time getting home without being a marker buoy on the road to other motorist.

Please help me if you can...and thank you for your time.

Kevin

 

[Evanson]

I have a 2011 and mysteriously at 105 k miles my fan wound not engage at idle with AC on. Found to be bad fan clutch. $450. later and an afternoon of fun the new clutch works great. Aerodynamically the fan looses its effectiveness at about 47 MPH. I installed a set of electric fans and shroud from Derale thinking that would solve the clutch problem. It did not, Ram spent a bunch of money designing that fan and shroud for max cooling. It will also engage if transmission (not Cait) gets warm. Best of luck.

 

[rashwor]

I suspect it is the fan clutch as well. I replaced mine this spring on my '05 and it works pretty much as it should now. I went with a aftermarket clutch and it does act a little different from the factory clutch did.

 

[gsbrockman]

It will also engage if transmission (not Cait) gets warm.

:-laf :-laf

 

[Matt_L]

I also had a similar problem last year where the fan wouldn't engage. After verifying with a snap-on diagnostic tool we determined it was the fan clutch. The speed sensor had failed. It was reading something crazy like 20,000 rpm @ idle. We replaced the fan clutch and all is well.

 

[KOwens]

Hey Guys...thanks for the replies. I've been out of town to AZ for 10 days. Had plenty of time to watch and think about this problem. Here is what I think I know about the problem.

1) fan works pretty well below 2,000 RPM while pulling grades while towing in hot desert/mountainous terrain. For me with a 68RFE transmission...that's roughly 60 MPH in 5th gear (first overdrive). Fan clutch kicks in at 219 degrees and kicks back out at 217 degrees. A light but not aggressive fan roar is audible if I turn the radio off. On my 1995 the fan noise when engaged was much more pronounced and really roared.

2) If truck automatically or I manually downshift to 4th...now roughly 2,400 RPM at 60 MPH...the fan clutch will not engage, period !!! Temperature will ramp up quickly under these conditions...A/C on...towing my travel trailer...hot summer outside air temperature...pulling a tough grade. Not good.

3) Coolant returns to normal temperature once the loading is remove (think done pulling the grade)...so I do not suspect a engine coolant thermostat problem...because once bad they will cause overheating even when NOT under load.

I don't own a snap-on diagnostic tool (only in my dreams) so I cannot recreate the problem in my garage...and I also have the extended warranty on the truck...so I will let them take another crack at repairing the problem later in the week. Since they replaced the ecm (truck bird brain) last time (shot gunning, right? ...since it did not solve the original problem), I think the fan clutch should be replaced next. Not much else to troubleshoot. We'll see.

Again, thank you all for responding...every bit of information is helpful...especially since the factory CD manual contain very little useful information for me. I'll post what I learn...once the truck returns from service. Thanks again for your input, Kevin

 

[slingshot383]

The most common complaint is the no cold air (air-conditioner) at idle at start-up. The TSB fix for that issue is the improved fan clutch. Now if that would also help with your condition is a good question. You're condition might be helped by extending the chin fairing down to force more airflow through the radiator instead of just under the truck.

 

[RustyJC]

Aerodynamically the fan looses its effectiveness at about 47 MPH.

Interesting statement since we tow a 19K GVWR 5th wheel. On a 100 degF day pulling a long grade at 60-65 MPH, coolant temperature will climb to 221 degF where the cooling fan engages and rapidly pulls the coolant temperature back down to 201 degF before disengaging. Based on my experience, the cooling fan is quite effective above 47 MPH....

Rusty

 

[kthaxton]

Interesting statement since we tow a 19K GVWR 5th wheel. On a 100 degF day pulling a long grade at 60-65 MPH, coolant temperature will climb to 221 degF where the cooling fan engages and rapidly pulls the coolant temperature back down to 201 degF before disengaging. Based on my experience, the cooling fan is quite effective above 47 MPH....

Rusty

Agreed, I used to think the fan was ineffective at around 45 mph too, but since owning my 2015, I now know otherwise. Same experience as above, I can be going any speed when towing, hit about 217º, then the I can hear the fan engage and watch the temp drop.

 

[KOwens]

A couple of comments/questions on the replies...

For 6Shaker...based on your troubleshooting, does that mean there is a speed sensor built into the fan clutch? Is that what your Snap-on test equipment was indicating 20,000 RPM at idle? Just wondering...again the CD service manual for my 2010 seems to have zero useful "theory of operation" concerning the fan clutch operation...so I'm in the dark on closed loop operation. If you know where that info is hidden on my CD, I'd love to know where to find it.

And for RustyJC...totally agree, when my fan clutch does decide to engage (usually around 219 degrees), the engine temperature drops rapidly, but disengages early at 217 degrees...NOT 201 degrees as you have indicated. Perhaps mine is cutting back out too early and should continue spooling until the temp is closer to nominal 200 degree "normal" running temp. Without fan clutch engagement, engine temp goes up equally as fast. Got to be a bad clutch.

Thanks again for the help guys!

 

[rashwor]

I am going to keep a watch on the behavior of my fan as well. I am not happy with the new one, but at least it does engage. The old one had got to the point where it was not engaging at all. Mine seems to fully engage at 1500 rpm (temp gauge at 200*) and below similar to the way my '99 did. Get above 1500 rpm and the temp will go up to about 205 and stay there and I don't rarely (if at all) hear the fan fully engage. I will be pulling hauling cattle in a few weeks and will be able to work it to know if it fully engages under load or not. This may help me to better understand if it is operating as it should or not.

 

[Bug Out]

KOwens, I thought on a recent trip up towards Flagstaff, that my clutch fan issues had disappeared. Same as yours, mine kicks on 217-220, then disengages about 212-210... On the trip up there, during night hours, I did not have the A/C on and the clutch fan acted like my other (2) Rams. Kick on 215-217, pull the heat down to 200 then disengage. I posted saying "devine intervention" but soon realized the big guy had nothing to due with it. On the road home, daytime, A/C on, the fan was up to its old routine.... I don't know if there's a link or not, but I'll have to test my theory again and see. That is, before I install a helper fan.....

The transmission(no relation to whats his name) did stay much cooler since I installed a MAG-Hytec pan.

 

[Evanson]

I have also installed a coolant bypass system that helps keep temps a little more constant. Interesting to hear your experience with the truck speed and fan effectiveness. I may have been told back info. It did come from a Ram tech but probly doesn't mean what it should.

 

[Cummins12V98]

KOwens, I thought on a recent trip up towards Flagstaff, that my clutch fan issues had disappeared. Same as yours, mine kicks on 217-220, then disengages about 212-210... On the trip up there, during night hours, I did not have the A/C on and the clutch fan acted like my other (2) Rams. Kick on 215-217, pull the heat down to 200 then disengage. I posted saying "devine intervention" but soon realized the big guy had nothing to due with it. On the road home, daytime, A/C on, the fan was up to its old routine.... I don't know if there's a link or not, but I'll have to test my theory again and see. That is, before I install a helper fan.....

The transmission(no relation to whats his name) did stay much cooler since I installed a MAG-Hytec pan.

Happy the pan is working well for you. My temps were always on the low side in all temps.

Pic of when I took it off my 11 I traded. The AMZ/OIL had about 45K or so on the oil. Looked great to me!

 

[Evanson]

Amsoil is great stuff. We have a Cummins in a OTR with Amsoil from new and we get 200,k between changes. Filters every 20,K.
On the subject of cooling fan, the pitch of blade, number of blades, rpm and air density determine effective cooling. On a '10 to '12 single wheel 3.73 in 6th at sea level on a 70 degree day 45 mph the fan is turning approximately 1194 rpm. Go to a dually 4.10 in 4th up hill at 45 mph and its turning about 2020 rpm. the more altitude the less effective the fan. I have been told that the t-stat on the 2013 up trucks is a 220 degree and that is why temps dump at 220 on the gauge. The largest effect on engine temp we as owners can make is engine rpm. Keeping the rpm up in the low to mid 2's while under load keeps the water pump, fan, trans pump and turbo pushing heat out. 70% of engine temp is eliminated by exhaust. When Ram started putting in the 68RFE in trucks they lowered axle ratio also. This helped with emissions but not helpful to engine and trans longevity. They did the same thing with the Aisin trans and 3.42 gears more recently. The big towing numbers are more related to brakes, frame, suspension, and drive line than raw torque numbers. The engine control program allows you to have up to 680 LBS of torque all the time. Hence the 68 in 68 RFE, the G-56 was originally set for 550 LBS of torque. With the Aisin, basically a 69 RFE, anything above 700 LBS of torque is available in 5th and 6th only. Why you may ask, well it is because of engine rpm and fluid flow for keeping **** alive. Look at the towing numbers of a F350 and F450, the only real difference is gears, oh and the cool front fenders. Same engine, trans, brakes and tires. Again engine rpm. Installing a lower temp stat can make a difference but unless you are willing to change engine control program this can have negative effects on performance. Changing to waterless coolant and a filter can make a great difference. Installing a bypass oil filter helps. Anything to get more fluids to take heat away. Probly the best trick is a Mishimotto radiator and intercooler, much larger and more efficient. Eliminating Egr cooler makes a massive difference.
I have removed every piece of emission equipement, large radiator, intercooler, camshaft, grid heater deleate, smooth boost hoses, intake horn, injector nozzle's, upgraded turbo, head studs, fire ringed head, 4" exhaust, exhaust manifold, water pump from mother Cummins from a 5.9 marine/ genset motor and custom engine tune. I am running 37" bfg at2's with stock 3.73 gears. Laying down somewhere around 700 hp at ground. A 2015 lays down somewhere around 325 HP at the ground. I recently went from north Florida to Maine and back with a 3000 lb lance bed camper and a 30' twin axle enclosed trailer with 2 911's in it. Around 23,000 lb. Shot up 81 into Virginia and pulled 6th, manually dropped into 5th just to see what temps did, came down a little but nothing major. When the truck was stock it would do this hill in 4th and 235 Degrees at 40 mph. This time I was pushing some sightseer in left lane at 65. I may have gotten of topic here many times but if any of the info helps that's great. Oh and I get 22 mpg empty on the interstate at 75. Cummins is the best!

 

[kthaxton]

The engine control program allows you to have up to 680 LBS of torque all the time. Hence the 68 in 68 RFE,

Where did you hear that? LOL!

The 6 is for 6 speeds. The 8 is for relative torque capacity, lower is less torque handling ability (i.e. Hemi's come with a 66 RFE). "R" is for rear wheel drive and "FE" is for full electronic control.

 

[RustyJC]

Hence the 68 in 68 RFE....

Ummm.....not quite. Go back to the 47RE, the 48RE, etc. 4 = 4 speed. 7 or 8 = tied to torque capacity (the difference between the 47 and 48 RE). R = rear wheel drive, E = electronic control (partial).

The 68RFE = 6 speed, torque capacity family of 8, Rear wheel drive, Fully Electronic control - thus, 68RFE.

Rusty