My 01 Dakota 4.7 (186k) overheats when towing. I do live in AZ and if it's cool (winter) it's fine. I made over 10 trips moving from Phoenix to Tucson area with a fully loaded trailer between Jan and March and didn't really have an issue until march when it started warming up.
I drove up to Phoenix in august and was having heat issues with an empty trailer and could barely maintin 50mph towing the loaded 6x12 enclosed trailer without the temps creeping up. At a few points I had to turn the heat on full blast (when it's 110 out) to keep the temps down and maintain a resemblance of highway speed. (50 in a 75 is dangerous and do not recommend) I always run O/D off when towing that trailer so the converter can lock up.

This week I found my filler neck is leaking so figured if I'm fixing that I might as well go all in with new 180deg t-stat, hoses, and maybe additional cooling.

My current radiator is one, 1.25" core.
I see the CSF 2 core being recommended here and does seem like a small upgrade. 2 core, 1.625 core thickness. 0.375" thicker than stock
Then you have the amazon all-aluminum 3 core ( https://amzn.to/3Vgw2ud) at 1.73" thick , 0.48" thicker than stock
And the amazon all-aluminum 4 core (https://amzn.to/499sBeB) , at 2.44" thick, 0.815 thicker that stock

Since I over-analyze everything, I wonder how having more cores in the same space affect cooling, in the sense that 1" single core will have more volume than 1" two core due to the unutilized space between the cores, but the two core has a hair more surface area for cooling.

Anyway, just trying to see what people think. I like that those amazon rads don't have plastic tanks, but do have concerns about the tranny cooler in them. Since I do tow with it, should I just bypass the integrated cooler and install an external one? Recommendations?

My goal is to have a vehicle that has OEM reliability (I don't want a project car) that I don't have to schedule my trips around the weather.

 

More cores transfer heat more efficiently to the air. (more surface area, simply due to all the edges) I might be tempted to go with the four core, given where you live.

 

Use the CSF. It's a known high quality product.

Not always. Two 1.5" cores actually radiates better than four 3/4" cores - has to do with volumetric flow efficiency.

 

Interesting. Fluid dynamics was never really my strong suit. I would LOVE to see some test results, or whathaveyou for that. Could be quite enlightening.

 

I recommended the CSF in this thread... https://dodgeforum.com/forum/2nd-gen...-radiator.html. However, it's not a double core, it's a thicker (1.63") single core....unless there is another CSF that I don't know about. Now this radiator has been in my truck for 11 years and counting and I haven't had overheat issues, unless I did something stupid like leaving the cap loose.... 11 years IS a long time, so maybe the ones you saw on Amazon are better, who knows? Am now sitting at 344K on original drivetrain with no rebuilds. The CSF is trusted and true, far as I"m concerned and your Amazon links don't work, so I didn't get to check those out.

Did your truck come with the tow package which includes heavy duty cooling? (run a build sheet to find out). If so, it would have the double core rad, as well as transmission cooler. If you have 1.25 either you don't have a tow package, or someone replaced it with a cheap AM rad. If you are towing with that in AZ, yeah that's a recipe for overheats, far as I'm concerned. I've towed a few cars between states on 8 hour drives with no overheats in the dead of summer. Make sure your electric fan is working as well and be sure to tow with OD off.

 

Thanks for the info! The build sticker is still in the glovebox. No tow package.

Everything I've seen on the CSF-3516 is that it's a 2 core. Maybe 11 years ago it was a single core(?)


What the amazon one looks like



One thing that boggles my mind is how the supply side of the Dakota radiator is not at the bottom. I do't think I've ever seen a radiator designed like that. So if your coolant is a little low, your pump starves?

 

Well hell, you may very well be right that something has changed since way back then. I researched that thing to death back then and distinctly remember it being single core at the time and now it says 2 rows even on the CSF website. I'd a take a dual core over a single any day, so If I have to replace, I'd go for the 3516 again.

Yeah, the 4.7 is a strange bird. First engine I've had with the thermostat at the bottom. Wasn't fun laying on my back pulling those little bolts for the first time back in the day...worried I was going to break them off. Not so bad now that I've learned to access them from up top while the fan shroud is out.
I don't think your water pump can starve in anyway that would cause damage. The coolant is expanded and pressurized for one and then the pump has a sealed bearing, not lubricated by coolant like back in the day. If you're overheating enough to damage a water pump, then the rest of your engine is already toast.

If you don't have the tow package, look into a tranny cooler, since you're towing heavy in hot weather. It all makes sense why you'd be overheating. It also included a suspension upgrade and trailer wiring IIRC.

 

Yes and no. Mostly yes.

Centrifugal pumps don't really pull much vacuum. So if the incident occurs that the coolant level in the tanks drops below the water pump, The pump will start cavitating and won't actually pull the coolant up to push it through the block. As such it doesn't matter if the suction port on the radiator is at the bottom or halfway up.

In a perfect world, the radiator cap's valve is working, and will draw coolant in from the tank as the coolant in the system cools down, contracts, and pulls a vacuum. And likewise as the system level does down, it will draw from the tank until the tank is empty.

Unfortunately, very little in a 20-year-old vehicle is still "perfect world".

When I was looking at cooling system options for my truck, I learned alot about cores versus core size versus radiator size.

I ended up with a 21" x 13" radiating area, utilizing 2 rows of 1.25" cores. I need more vertical size but can't physically package it. I am using an expansion tank which plumbs into the lower (suction)radiator hose, similar to some diesel setups, and receives a small amount of coolant from the steam return lines at the back of the intake manifold. The expansion tank has the radiator cap which goes to a bottom-fed overflow tank. Ideally once the system balances, the suction side of the pump is always kept wet, between the expansion tank (which empties slowly) and the radiator (which empties quickly)

 

I suppose, if the engine lasted long enough without coolant, it could damage the pump but the fact is, it won't. The head will be blown followed by block fusion and by then, your pump cond won't even matter.

 

I ended up going all in for the 4 core.

Certainly not the best specimen of aluminium welding.
I found it odd that on both sides of the top 2 rows, they have some sort of metal piece mostly plugging the cores.




The thing I was most concerned about was what kind of tranny cooler they were using. Seems to be a pipe with some sort of expanded metal in it. (I stuck a borescope in the end tank)
At first I thought they left machining swarf in the hole, but whatever it is in it is rigid. I always assumed the OEM radiators used some sort of stacked plate heat exchanger. I wonder about the effectiveness of this one.



I was on the fence about adding an external cooler, now maybe I'm on the side of doing one.