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Discussion Starter · #1 · (Edited)
I have a 2010 Mega Cab dually, fully deleted with a EFI Live program. I tow a 42 foot fifth wheel toyhauler that weighs around 21000 fully loaded. I'm having trouble heating on long hills. Like for instance, it was a 93* day on a long hill(north of Ashton Id) it's a few miles long but when I hit the hill, I'm on 3 on the control which is tow mode and the truck pulls good, then starts to get warm, I heard the fan kick in at around 220(is that normal) and just keeps getting hotter. I turn the program down to 2(not much above stock) and start backing off on the throttle and for the last couple of miles of the hill, I was in limp mode and doing like 35mph and still at 235 plus. Semi's were passing me, never mind the Duramax with a 40' fifth, who went by like I was sitting still, smirked at me and apparently wasn't hot like me, LOL. I had an 08- 6.7 Mega cab, and it would climb that hill with a similar trailer on the rug the whole way, and stay under 228.
Question is, is this normal, or can I get a bigger aftermarket rad? Or is the fan getting weak?.......... I need to fix this.
(I have tried hills with the programmer turned off, the rad, intercooler and AC condenser were all removed and cleaned not long ago.)
 

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While I am definitely more familiar with 3rd gen trucks, the cooling systems on all these trucks are already oversized for the job they do.

For instrance, the only time (knock wood ;) ) my truck has ever overheated towing is when I let the coolant level get MUCH too low due to an unnoticeable and minor leak going on for much too long.

Things to check first, in order of importance, are :

1) Coolant level
2) Cleanliness of radiator and AC condenser that affects airflow through the radiator
3) Proper fan clutch operation



All that said, you should also detune your truck to see if the same thing happens,,,if possible on the same or another familiar grade where you can do a side by side comparison.

Just my .02
 

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Discussion Starter · #3 ·
While I am definitely more familiar with 3rd gen trucks, the cooling systems on all these trucks are already oversized for the job they do.

For instrance, the only time (knock wood ;) ) my truck has ever overheated towing is when I let the coolant level get MUCH too low due to an unnoticeable and minor leak going on for much too long.

Things to check first, in order of importance, are :

1) Coolant level
2) Cleanliness of radiator and AC condenser that affects airflow through the radiator
3) Proper fan clutch operation



All that said, you should also detune your truck to see if the same thing happens,,,if possible on the same or another familiar grade where you can do a side by side comparison.

Just my .02
I did leave some things out of my post, my bad, LOL. The rad, intercooler and ac con, was removed and cleaned properly not long ago. I did try it other hills with the programmer turned off and it it still got hot.
 

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The rad, intercooler and ac con, was removed and cleaned properly not long ago.

Ok...you should still check your coolant level.


Is your truck an automatic ??... it is possible that the TC us not locking up properly and contributing to the overheating through the AT cooler.

That said, I know VERY LITTLE about that though as I have always driven manual tranny trucks.
 

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Discussion Starter · #5 ·
Ok...you should still check your coolant level.


Is your truck an automatic ??... it is possible that the TC us not locking up properly and contributing to the overheating through the AT cooler.

That said, I know VERY LITTLE about that though as I have always driven manual tranny trucks.
Coolant is good, head gasket is good and tranny temps are good. I wish it was a manual! :)
 

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2007 Ram 3500 5.9, mostly stock
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Well I also know the 3rd gens much better but the fan should kick on way before 220 degrees, if it was mine I'd be backing off on the right foot at 220. Any idea how many hp you are adding with the tune you are running??

The only time I had an issue with overheating was grossing about 32k on a steep mountain on interstate with a brand new junk Dorman fan clutch that blocked more air than it blew, I was running a 50hp tune but it would overheat extremely easy. I ended up beside the Rd bubbling over at 245, it was not a fun experience.

How many miles on the truck??
 

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Discussion Starter · #7 ·
Well I also know the 3rd gens much better but the fan should kick on way before 220 degrees, if it was mine I'd be backing off on the right foot at 220. Any idea how many hp you are adding with the tune you are running??

The only time I had an issue with overheating was grossing about 32k on a steep mountain on interstate with a brand new junk Dorman fan clutch that blocked more air than it blew, I was running a 50hp tune but it would overheat extremely easy. I ended up beside the Rd bubbling over at 245, it was not a fun experience.

How many miles on the truck??
200000 on the truck, 15000 on the new engine. I believe the EFI Live is 50 or 60 on 3. I was told that the fan is supposed to kick in at 220. Maybe my fan is bad, but I can really hear it after 220.
 

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2007 Ram 3500 5.9, mostly stock
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Im sure it should kick in before that.

Did u ever install a new thermostat or fan clutch?? If u did was it oem or a knock off parts store junk??

Hopefully a 4th gen super tech will see this and help out
 

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Programmed 217f on my model year for Cooling fan.
 

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Discussion Starter · #10 ·
Im sure it should kick in before that.

Did u ever install a new thermostat or fan clutch?? If u did was it oem or a knock off parts store junk??

Hopefully a 4th gen super tech will see this and help out
New thermostat with the new engine, but didn't change the fan clutch. The thermostat seems to work good, when it's not working hard it just sits between 190 and 193.
 

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The emissions set up on our model years I think dictated the higher temperatures.
Do you have a reference for your exhaust gas temperatures?
 

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Yup, about the same on mine. If they don't want these things over 220 they should be turning the fan on sooner.
I’m wondering if you have an aftermarket 190° thermostat that is not opening all the way…..
 

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The emissions set up on our model years I think dictated the higher temperatures.
Do you have a reference for your exhaust gas temperatures?
Yes it reveals my absolute ignorance, I don't know exactly when mine kicks on high but I thought it didn't have to heat up much at all and it was screaming.
 

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How much HP were you running ? Being deleted is not a big deal. If you are pulling that much weight I wouldnt go over 30 HP. Sounds like you have an issue with the cooling system
 

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Discussion Starter · #17 ·
Has anyone tried one of these? If so, how much did it drop your temps?
 

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While that Mishimoto is certainly a nicely built radiator and might look really good in someones highly tuned custom build, I have NEVER heard of anyone getting an actually substantial in use towing temperature drop by installing one. At best, it might take a little longer to get to the higher temps that you seem to be experiencing.

That said, I'll bet that at least 98% (prolly even more ;) ) of Dodge Ram CTD owners are still using the oem radiator and cooling system and do NOT have overheating issues even while towing heavy.

Again, If the OEM cooling system cannot keep up with your trucks towing temps, something else is going on...you are towing too much, you are towing with too much of a tune, or something in the oem system is out of spec or needs attention.

If you want throw parts at your undiagnosed problem, it would be MUCH cheaper and easier to buy a Cummins oem thermostat and replace the one in your truck, just in case when you previously had the cooling system serviced, someone installed an aftermarket one that is not functioning properly or maybe the original has gotten tires and is not opening the whole way.

Or maybe the cooling fan clutch is not operating within specs and should be replaced with an OEM unit.

In short, and most importantly, I don't see how the MIshimoto radiator will change anything about your towing temps if you do not diagnose the underlying malfunction leading to the high temps.

That said, if you have some extra money burning a hole in your pocket and you want to install a really nice looking and nicely built radiator... go ahead and install that Mishimoto, and then pull that same grade and let us know the results.

Just my .02
 

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New stat or not, I would check your thermostat on a stove in a pan of water. My experience has been… Cummins and my Genos Gates thermostats open about 5/16 and parts store thermostats only open about 3/16.
were your coils cleaned with a pressure washer, shooting straight through, so it blows all the crap out of the fins? That’s the only way I do it and I’m always surprised at the mud and bugs that come out..
My thermostat also has the bypass disc so when the thermostat is all the way open, the bypass is closed so all the flow goes through the radiator and none of it short cycles back through the engine.
I valve off the heater core and my water filter in the summer, otherwise that water will also bypass the radiator.
^^^ I tow heavy in the mountains with a very heavy foot and added power and that’s how I keep my 12 cooling good.
 

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How do you know it's not your head gasket? How did you determine that head gasket is good?

I had exact same symptoms and it was head gasket.
 
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