Let’s talk about egts and water temp

asmith

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I know you have spent a lot of time fixing and painting your truck. but have you considered a cowl induction hood? get a little more airflow through the whole engine compartment. Not sure if it would help much, but I have always liked the looks of them.
 

laserjock

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I know you have spent a lot of time fixing and painting your truck. but have you considered a cowl induction hood? get a little more airflow through the whole engine compartment. Not sure if it would help much, but I have always liked the looks of them.
I have considered it. I’m not a huge fan on these trucks. I also considered some extra vents in the fenders and through the air dam.

Spent a little time looking at air/water IC’s. My buddy has a kit he hasn’t used yet. Still have the where to put the Rad issue but I’m trying to think ahead to what may be the best option if ultimately the problem is too many BTUs into the rad or not enough air through the rad. They both kinda lead me in the same direction. IC would have to go because I’m not loosing the AC.
 

Big Bart

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Thanks for the responses.

Yes it’s my truck in the Sig.

Radiator was a new champion when installed.

Typically if I’m pulling hard I’m in 4th turning 2300-2500 rpm.

I have very much considered that it still may be an air flow issue as the fan helped but like I said, didn’t quite get me there.

I’ve considered pulling the IC just to see what it does. I don’t want to keep it that way but I could do it as a test.

It’s certainly worse with the AC on.
Sounds like you did all the basics.
1) Thermostat, check
2) Timing, check
3) Radiator, check
4) Fan and clutch, check

If not a giant hassle pull the IC and test. You will know if that helped the radiator cool better.

A potential factor is your 3.55 axle, the 4.10 is better suited for towing heavy. But others can weigh in if their 3.55 axle has heating issues when towing heavy up a grade with your same tranny.

Yes if your turbo is water cooled that is not helping either.

To your comment that you are not a fan of these trucks, you have to be realistic about what they are and are not. They are not PowerStrokes and thus they lack HP. With an IDI you get into a diesel or less money and give up HP for simplicity. As a daily driver and for towing light they are great and comfortable to drive.

As a 10,000 lb tow rig they leave a lot to be desired for sure. Many a member started with a cheap IDI and pony’d up for a 2000-2015 modern turbo diesel truck for various reasons. IDI’s are very capable but have their limits. Some need more hp for daily use or towing a larger load frequently. You have to decide what is right for your needs.
 
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Black dawg

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get some top tank vs bottom tank temp numbers, that should tell you if the radiator isnt removing enough heat from the coolant. Cooling system design theory shoots for 10 degree temp drop at full go.

I wish I could remember the numbers, but it seems like on my truck I was seeing almost 100 degree top to bottom temp difference wich tells me coolant is spending too much time there. The hotter you can get the radiator....with good airflow, the better it works.
 

asmith

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I have considered it. I’m not a huge fan on these trucks. I also considered some extra vents in the fenders and through the air dam.

Spent a little time looking at air/water IC’s. My buddy has a kit he hasn’t used yet. Still have the where to put the Rad issue but I’m trying to think ahead to what may be the best option if ultimately the problem is too many BTUs into the rad or not enough air through the rad. They both kinda lead me in the same direction. IC would have to go because I’m not loosing the AC.
I have an air to water cooler on my truck and love it. the radiator portion up front is much smaller than an air to air and thus blocks less area.
I am currently waiting patiently for a new 110cc pump from CCD to go with my new turbo that is sitting here on my floor. once all the parts show up I will be interested to see how my temps do. I am hoping they drop a little from the better turbo and air flow.
 

03wr250f

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I would be willing to bet the turbo is definitely dumping additional heat into the cooling system.
@goosemay chime in and say the same thing. I don't know that 3.55s are hurting you that much. Because of the similar trans ratios, simply drop a gear. As you know op
For the rest of you 3.55 4th on a zf5 is almost identical to 5th and 4.10s
3rd 3.55 is close to 4th 4.10 etc.

How old is your ac condenser. I just replaced mine for high pressure at idle issues, but what I took out is a dual stacked plate condesor looking like an old trans cooler. What I put in is built more like a intercooler 1/2" fin spacing and large tube design. I am sure it will help airflow though the cooling stack. Might be something to look into.

I believe @lasermeant he doesn't care for hood scoops/big hoods on these trucks. But I could be wrong

@laserjock you monitoring oil temps by any chance? It may be that oil is getting too hot cooling the underside of the pistons, and thru the oil cooler transferring to coolant. Would be good to know. Again along the more data line.

And this doesn't help now, due to the backlog of flowkooler water pumps, might be worth trying a high flow water pump see if that helps.
They claim it increases pressure which brings me to my next point
What brand and psi rad cap you running
Stant (rebranded napa house brand) are what I found to be the best.
Also might try going from a 13 psi to a 16 psi.
Do you have a spring in the lower rad hose
Do you have a shroud on the rad?
 

laserjock

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I love my truck. I spent a lot of time and money to get it to where it is. I’m 85% there. If I could lick this problem, I’m 95% to where I want to be. That last 5% will come later with the next project. I’ve got enough power I just can’t use it all.

I’m eyeing a drop to 3.73 gears in the future because all I seem to do is tow. It doesn’t solve all the problems but it wont hurt.

I am not running oil temp gauges currently.

I have a 7 lb cap on it now. I had a 13 lb on it for a while and developed my freeze plug leak.

Yes I have a really good fan shroud for the big fan. Seals way better than factory.

@asmith what size unit did you go with. My calculations show a 450 cfm unit will be sufficient and the frozen boost unit for that size does have a small radiator. The next size bigger has a pretty large rad although it’s only 1” thick.
 

Timm

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Hi, I may be late to the party, but this is a topic that is of great interest to me. I have a 1993 7.3 idd N/A with a hypermax pulse turbo setup, e4od, 4wd dually(I did the dually coversion) crew cab XL truck (no intercooler, intake is through the wiper cowl). I make 8 to 9 psi of boost. I run 235 85r16 tires. I am seeing some heating trends that I don't like in my truck as well. I tow a 8250 dry(add a generator and all the camping stuff to make whatever is reasonable here for total weight) 5th wheel, with a full cab of family. Before the turbo truck was slow as can be on some hills but temp gauge never moved from the low side of normal. I now see the temp gauge move right from the middle of the normal to the "l", and then it can hang out there near the "a" and "l" when I am doing 65 with it. I was a little (less than 1/2 gallon)low on coolant and that helped some, but I still don't like to see it up there plus it's hot in the cab. My EGTs in that condition are 11 to 1150 degrees and I'm in 3rd gear, with a stock pump slightly advanced and turned up supposedly 2 flats. When running like this it gets real hot in the cab which is not comfortable. I had to remove the firewall rubber and insulation and replaced it with thin fiberglass/aluminum reflective mat(it's not enough). If your coolant is old, flush the system first and foremost. I too am thinking of ways to get more air past the firewall faster, in hopes that there ends up being less heat to shed at the radiator. I was told that the transmission could be equally to blame as the engine for my Temps. I do have a stock cooler for now, but was going to try an aluminum transmission pan next. I also seem to see that based on injection timing and amount, more diesel fuel earlier will let the engine run cooler(as long as egts aren't going past safe limits). It also seems plausible that the intercooler could be blocking some of the airflow for the radiator. Do they make an aluminum oil pan for these engines? I should mention I have been running some +8 cetane improver and my engine loves it, I cannot believe the difference. I have heard about a aluminum radiator upgrade that has more cores but fits in the same spot... I am sure that the 3.55s are causing some of these "threshold issues" with heat that we are talking about, but.... if we didn't see this problem at the weights we are talking about towing now, we would at a higher towing capacity anyhow. I love tinkering with this truck and trying to get it to do more, it's fun, and I couldn't afford to mod the new stuff anyway, I don't have an uncle Elon. Has anyone tried taking off the front bumper? It would seem that there is air to be brought in if that wasn't in the way... or are there "more open" bumpers that could be used? Taking it off for a short trip could be a good way to see if there is anything there. I am interested to hear what you or anyone else might do to help this situation out. I heard the cowl induction hood suggested and it would seem that you need the air brought in more to the front to have any meaningful impact... like adding a super duty hood from 2000 and leaving the middle portion open(I know it doesn't actually fit, but as a concept...)
 

Big Bart

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Injection pump timing can cause the engine to run hotter pulling heavy at hwy speeds. What is your timing set at now?

Also if you are referring above to your stock dash temp gauge it is not accurate, you might want to think about a aftermarket one. But you sense more heat in the truck so likely it is getting hotter under the hood.

3.55’s are not as ideal for towing heavy, truck is working harder to keep the hwy speed. Great for mpg though!

Adding centane is likely adding BTU’s. (Heat.) In the old days when folks timed these IDI’s via the lummy method (Flash of the diesel burn via a special glow plug.) centane was considered as part of the timing equation. So you may be advanced by timing adjustment and then slightly more advanced via adding centane. (Burns faster thus advanced and I believe hotter thus more heat.) I am no expert here so just something to consider. Maybe test run with centane (Front tank) and without centane (Rear tank) to see where your heat level is with and without. However your stock dash guage is not going to show you much if any difference. A decent aftermarket gauge will.
 

david85

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I'm impressed at your ability to control EGTs so well. My thought is to measure the intake temperature while pulling a long hill and see how high the temperature is really getting. If you're seeing intercooler temperature comparable to your thermostat temerature, then it stands to reason that some efficiency will be lost on anything behind the intercooler.

On the other hand, any cooling that happens in the intercooler should (in theory) reduce the amount of heat in the engine by the same amount...unless it gets so hot as to effectively prevent heat transfer at the coolant radiator.

Seems to me that you've already upgraded the cooling system with a bigger fan. You could investigate a bigger water pump but I'd start taking more measurements before throwing more upgrades at it. Upgrades are nice though...
 

Nero

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A good portion of semis I work on actually have the intercooler take up 1/3 of the front end space, then the radiator takes up the other 2/3 of the fan area, to prevent heat soaking of the radiator to to the CAC. Something to ponder.
 

Black dawg

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Something I always forget to mention in cooling threads, is that the fan and crank pullies are interchangeable and different sizes. I have seen people put the bigger pulley on the water pump....
needs to be big pulley on crank and small pulley on water pump.
 

Booyah45828

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get some top tank vs bottom tank temp numbers, that should tell you if the radiator isnt removing enough heat from the coolant. Cooling system design theory shoots for 10 degree temp drop at full go.

I wish I could remember the numbers, but it seems like on my truck I was seeing almost 100 degree top to bottom temp difference wich tells me coolant is spending too much time there. The hotter you can get the radiator....with good airflow, the better it works.
Agreed. Those numbers will show how efficient the radiator/fan is working. I'm not sure on the 10 degree number, but I've never checked one that was functioning normally to know what it's supposed to be. Typically I'll see no change(poor fan/air flow) or too much of a change(clogged radiator)
 

Booyah45828

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Something I always forget to mention in cooling threads, is that the fan and crank pullies are interchangeable and different sizes. I have seen people put the bigger pulley on the water pump....
needs to be big pulley on crank and small pulley on water pump.
Didn't know that one. Not sure on how big of a size difference between the two there is, but any size difference could contribute to an overheat issue due to slow water pump/fan speed.
 

Black dawg

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seems like wp is 6.5 od and crank is 7.25 I will try to measure later today
 
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