First tow, and she ran hot - who has improved cooling system?

[Jim73]

Well, my first tow with the IDI was a fiasco!

Pulled my 22 foot travel trailer (5800 lbs) up I-15 through Vegas en route to the Grand Canyon North Rim last week. Pulling Cajon Pass northbound, noticed that the temps were coming up and the fan clutch wasn't engaging (at least I wasn't hearing the usual roar...) and she overheated.

To make a long story short, finally limped to the Canyon with no A/C useable and the heater blasting to keep coolant temps in check. Had to stop several times to cool her off - cracking the hood and running her at elevated idle revs was effective in dropping temps slowly. The fan RPM seemed to come up along with engine revs to about 1800- 2000, but it wasn't engaging with that airplane roar as revs were increased. The weird part, though, was that on the way back down after a week at 8000 feet and in cooler temperatures, the clutch began working as we dropped into moderately hot areas east of St. George, Utah. I hoped that a miracle cure had taken place (maybe some silicone had leaked INTO the right place in the viscous clutch during the stay up high?) but that hope was quickly dashed once we got down into the real hot sections of the desert. The drive home was misery - it was 114 degrees in Baker!

Before the trip, the cooling system was flushed and coolant replaced, along with SCA recharge. Around town before the trip in low 90s without the trailer, the fan clutch was engaging, so it seems like it works until you really need it, then goes on a break!

I'm assuming replacing the viscous fan drive is needed, but disturbed by the marginal cooling I seem to have. Has anybody done effective cooling system upgrades? I'm considering replacing the radiator, adding supplemental pusher fans, and so forth. Has anybody had success with these types of mods - especially anybody towing high and hot? How about adding external engine oil coolers in addition to the bundle on the block? (Yeah, I know, I'm grabbing for straws, but the high temps REALLY had me worried about the oil breaking down. Hopefully the tranny is OK, but time will tell. Might look at a fan-assisted additional trans cooler, too!)

What has worked for you guys?

Jim

 

[argve]

Been there done that...

Ok what I found in my trials..

Extra fans don't do anything except take up money and time to install - they add no bennies in fact I suspect they hurt ya once up to speed.

Make sure the rad and ac condensor are clean, bug free and the fins aren't folded over.

I ended up getting a custom built rad for The Enterprise it's used the stock tanks but was 4 core (dimpled) and double the fin count - trust me this was a cooling SOB - I could not make it overheat no matter what I did - my main test was right after getting it installed was to pull "Jellico" (major grade here in the eastern US on I-75) with my foot firmly planted to the carpet. I looked over to Sherri and said I'm gonna either blow her up or she will stay cool. My thinking was I was tired of dealing with it - I placed a call at the top of the mountain grade to the guy that built the rad - My words to him were "this rad is a cooling SOB" He was pleased as I was...

You can find the information for the rad in the history here as I know I have posted it. Trust me I did everything for my cooling issues but dance naked with chicken and a big stick around a campfire. I even made scoops to force more air across the rad to no avail. Trust me the rad did the trick.

Now I'll warn ya it's not cheap but if you really want to stop the overheating in it's tracks then this is the way to go.

I know I sound so firm about it but trust me you wouldn't believe how long I fought the higher temps. It first reared it's ugly head while out in South Dakota when the air temps were 101° starting to pull into the mountains. I replaced everything in the cooling system many times - even new stock rads, modified fan clutches, and cooling opening thermostates... ended up the rad was the trick...

 

[argve]

Here is the post I made so long ago...

Ez..

HRC Heatex-Spec Heatex HD-Core
FD-Truck 23 5/8 x 30 3/4 x 3

I traded in a Heatex PC/LT Core

This was the radiator I put in The Enterprise when I was fighting high water temps after the turbo install. I coupled this with the modified fan clutch from MS TECH >>> Click Here <<<

They are currently not taking orders online but if you get them on the phone they can set you up. I think Darrin just got his for a little over 200 bucks.

I installed both the new custom rad core and fan clutch at the same time. I could watch the thermostat cycle after all that so the fan clutch was not kicking on unless I was pulling a hill in the hot weather with the A/C on full blast. It took quite a bit for the fan clutch to kick in after the radiator.

Travis.

 

[Jim73]

Thanks, Travis!

Pretty much the way I've been thinking as the day has worn on and I was unhitching the trailer and mulling things over. Needing the fan to survive at highway speed spells inadequate heat rejection to me! I am right with you on wanting to hit this with a large caliber, possibly overkill solution so it ceases to be a concern!

I'll give those guys a call tomorrow...

Jim

 

[Darrin Tosh]

I agree with Travis, Whenever you add a turbo and dump a bunch of fuel into these trucks to make more power, you heat em up quick. The stock cooling system can't keep up. I would think that you are running at pretty high RPM's with the C6, and no overdrive.

I have done the same thing as Travis has, New "stock" Rad, Holes in the bumper, Scoop under the front, modified fan clutch etc. Get the bigger radiator, and you will be all set.

I pulled my 30' fiver this weekend and it runs at 200 to 210 at 60 to 65 mph. If I want to do 70 to 75, then it will start to warm up. That is here in MI at 85 deg temps and no mountians.

I have just learned to slow down a little, (yes it is hard), and keep the temps at bay untill I spend the money on an big rad.

Let us know what you do!
Darrin

 

[reklund]

Any thoughts on converting to a PSD Aluminum radiator? Is it even do-able without major fab? I know the PSD's use a pressurized overflow system, but could it be adapted to work on the older IDI's?

Ryan

 

[argve]

I never looked at using a rad from another vehcile figured that if any custom work needed to be done that it might as well be in the rad that way it's was a drop in deal and if by some chance that I hit something or someone pulled out in front of me while I was 1000 miles from home I could have a local shop drop in a stock type rad and drive home slow... but I guess you could while out there have them drop in a PSD rad just the same but they (shops) like to put in stock parts because of liabiltiy issues..

 

[MIDNIGHT RIDER]

I don't know what kind of radiators you guys are running that are giving you the overheating troubles.

My old 6.9, with near a half-million miles, and the original radiator, with a Hypermax turbo and the fuel cranked, never got above normal, pulling big loads of cattle on 100 degree plus days, running maximum A/C.

I kept my foot in it and have never had an overheating problem.

I would suspect that an automatic would probably overheat; but, an automatic isn't gonna start the kind of loads we pull.

 

[Agnem]

I think the 6.9's have a definite cooling advantage over the 7.3's. One of the big differences between the two, is the blocked off cooling system passages on the 7.3 heads. Not sure why they did that, but I think the water actually gets hotter in a 7.3 than it does in a 6.9. Just my theory. Also, the earlier non-AC 6.9's with the extra wide radiator have better cooling properties.

 

[Jim73]

Midnight Rider,

Stock radiator, only mod to powertrain other than deep trans and diff covers was the ATS turbo installed in 92. Stock injectors. It was VERY hot, but that's a fact of life in the western desert in summer. Without a fan clutch engaging, this thing simply will not cool at highway speeds in this environment unless you're on flat ground - the slightest grade sent the needle to the right even with A/C off and the heater roaring. I'm not expecting to steam up grades at 75 mph, either - 60-65 with the trailer would be just fine, and I let speed drop for the really nasty grades. The truck has plenty of punch for this and EGTs have been fine.

Maybe there is crud in the cooling system I can't see and a flush failed to remove. Maybe the radiator passages are partly restricted by scaling or something, but it isn't apparent looking at the passages I can see from the cap opening. I don't know. All I know is that this thing isn't shedding heat fast enough for my conditions.

Jim

 

[MIDNIGHT RIDER]

Let me get my flame suit on.

Okay, here is an old trick that I have used on a few occassions.

I have had a few vehicles that have gotten hot, on account of non-functioning fan clutches.

I drilled through the fan-clutches and pinned them, such that they turned constantly, so long as the engine was running.

Those vehicles were driven for years with the fan-clutch pinned with no issues whatsoever.

One thing for sure, the fan worked real good, none of that pansy slipping stuff.

 

[Jim73]

No reason to flame you on that as far as I'm concerned, MR. Just a matter of whether you want to give up the power/incur the drag when the fan isn't really needed. A rigid connection to the pulley would certainly be reliable, if a bit noisy.

Jim

 

[reklund]

Some things I've learned about cooling systems, being a professional mechanic in the Desert Southwest (New Mexico...)

1. Your old radiator isn't in as good of shape as you think it is. Unless you flushed your coolant every 30k miles and replaced it with the proper SCA additive, and DISTILLED water, it's full of crud. That nasty tap water fills the system with minerals and calcium and all sorts of junk that accelerates the corrosion in your cooling system. You'd be wise to replace most ANY radiator over 10 years old, especially if it has a questionable service history.

2. Factory parts are your friend. You can probably get away with an aftermarket radiator, but don't cheap out on aftermarket water pumps, fan clutches, thermostats, or anything else related to the cooling system. There IS a difference. Sounds like your fan clutch is suspect anyway, I'd vote for a replacement while you have that radiator out...

3. The biggest aluminum radiator you can find will definitely help. With a little research, the PSD radiator from a 95-97 PSD might work. I helped a friend install one in his PSD and it was a nice 100% aluminum 4 core unit from Performance Radiator. I believe it was under $300, IIRC. The pressurized overflow bottle nonsense could be worked around, if you can find someone to weld a conventional "cap" neck on the tank for you. I believe the PSD's have crossflow radiators (tanks on the sides) but you could still get it done with some custom work.

I've been battling overheating issues in my 400HP Supra for years now, and just last week broke down and put in a 4 core aluminum radiator. No matter how hard I beat on it now, it doesn't even TRY to get too hot. 100 MPH pulls at 25psi don't phase that car anymore- and those cars are notorious for overheating. You can bet that when the time comes for a new Radiator for my F250, it'll get a badass aluminum unit.

4. The proper ratio of coolant:water is important too. Coolant can't carry away the heat like water can, but you can't run straight water. Be sure to follow the reccomendations for the mixture according to your climate. 50/50 is fine for most folks, but if you live out here (where it doesn't get much below 20°F in the winter) you can run more water. If your rig is plugged in at night in the winter anyway, that's a little more insurance too.

I saw a car at work once that was running straight antifreeze, and couldn't keep cool very well. It wasn't overheating, but it was running "warm". Turns out dude had filled the system with straight antifreeze the last winter, thinking it was pre-mixed.

Hope this helps-
Ryan

 

[Jim73]

Thanks, Ryan!

I'm pretty much decided on the radiator replacement - either Travis's guys or somebody who can give me a comparable unit. The truck sat for a couple of years before my Dad realized he would have to hang them up and offered it to me, but prior to that he performed annual coolant flush/replacements at a local radiator shop prior to each towing season.

Definitely planning to do the fan clutch while the radiator is out - hate to pay dealer prices, though. Your comments are interesting and might tip me in that direction, but I'd hoped I could find out who Ford used as a vendor and if they market the same piece elsewhere. Any insights there?

I don't go to extremely cold places often - the worst I normally see is in the mid-twenties. Will keep that in mind when setting up the ratios.

Hopefully, I'll get this stuff done in the next two weeks and I'll be able to report after our next tow (late July/early August) that the cooling issues are licked. Thanks again, guys!

Jim

 

[reklund]

Jim-

I know that the dealer prices are hard to swallow, but you need to keep in mind that they're easier on your wallet than the tow bill from the middle of nowhere.

I'm a bit biased, as I removed faulty aftermarket parts all the time as part of my job. You'd be surprised at what a little sweet talking will get you at the parts counter though. Just asking might get you the part at wholesale cost, which is usually 20-30% below retail.

GOOD LUCK!
Ryan