Running Hot ? what to do ?

[DMorris]

2003 , 6 speed, 4:10 gears, Edge juice ( set on zero-monitor only), smarty s06 on 4 (no timing) , high flow intake and exhaust. Electric fan kit cant remember the manufacturer at the moment but its about the most common set up out there. My clutch on the stock fan went and I swapped to electrics a few years ago. Not that it matters but my water pump is also fairly new.

I am pulling pretty heavy (18000 fifth wheel).

question #1 - what is too hot ? I am am running up to 220 on small grades.

I never seen temps this high on my truck. I have heard that is not to worry about ? But I would like to hear from others.

I worry that during the summer when pulling long steep grades in the south west I will over heat.

question #2- what can I do to reduce the temps. My fans do run fine but really as long as I am moving at a half way decent speed I would think it should not run too hot ?



I have limited funds but about two months to try to get this taken care of, please advise.

 

[wlowe]

I would check with the electric fan manufacturer to make sure the fan is rated to pull that much weight. Sounds like it isn't moving enough air.

 

[Prairie Dog]

First, 220 is not too hot. Second, It seems almost impossible that an electric fan could keep up. The stocker moves so much air that it takes >20 HP to run it at full power. An electric fan would have to draw way more electric power than the truck could provide at those levels of performance. I may be wrong and I'm open to learning if theres some better way to cool the Cummins.
If elect fans work, why don't the big three use them?

 

[Azelgin]

I have an 01 that had temperature flucuations that were driving me nuts! It would run at a normal operating temp until I put a load on it and then, it would run up to 210~220. Never did that before. Took out the radiator and gave it good cleaning. No change. Finally decided to take a look at the thermostat, even though every thermostat problem I ever had never did this. Turns out the rubber ring around the thermostat disc had a notch in it. the thermostat would work normally, until it opened wide. When it did, the notch would allow the rubber to flop off the disc and retrict the coolant flow when it was needed most. When it cooled back down and closed, the rubber returned to its proper place and the thermostat worked normally. Worth taking a look at.

 

[JMarketos]

I didn't see mention if this issue is new- have you pulled 18K in the past (with the electric fans) without heating up?

I had an S-10 blazer many years ago and I noticed the coolant temp started to rise anytime the engine load was slightly above normal. I installed an aux electric pusher fan, not figuring it would help (and it didn't). Long story short, cause of that heating issue turned out to be a radiator in which the ends of the cross tubes were getting corroded and restricting the coolant flow. Replacement radiator fixed it.

Depending on answer to first item above, sounds like recommendation is to look at the T'stat and look at the cross tubes inside the radiator. You may have to drain some coolant out to get a look down in there.

I don't know if these engines have plastic water pump impellers that are prone to losing vanes ?

 

[Wingate]

2003 , 6 speed, 4:10 gears, Edge juice ( set on zero-monitor only), smarty s06 on 4 (no timing) , high flow intake and exhaust. Electric fan kit cant remember the manufacturer at the moment but its about the most common set up out there. My clutch on the stock fan went and I swapped to electrics a few years ago. Not that it matters but my water pump is also fairly new.

I am pulling pretty heavy (18000 fifth wheel).

question #1 - what is too hot ? I am am running up to 220 on small grades.

I never seen temps this high on my truck. I have heard that is not to worry about ? But I would like to hear from others.

I worry that during the summer when pulling long steep grades in the south west I will over heat.

question #2- what can I do to reduce the temps. My fans do run fine but really as long as I am moving at a half way decent speed I would think it should not run too hot ?



I have limited funds but about two months to try to get this taken care of, please advise.

220 while pulling isn't bad if you know your cooling system is operating properly. I would think one can run up to 235 fairly safe with the proper pressure cap.

Are the fans on a temperature switch and run in auto mode? or are they immediately on with keyswitch power? If they are on a thermostatic switch, what temperature do they cycle on/off? And is it operating correctly?

When the fan is running do you feel strong airflow infront of the radiator/intercooler/condensor assembly?

This is a common area for dirt and road grime to get packed up between the different cores and cause air restriction, leaving you will a poor airflow condition that causes overheating. If your monitor watches IMAT, are you noticing an increase in inlet air temperature?

High torque loading at low rpm can also cause an increase in coolant temps. .

 

[JBallou]

T-stat or radiator cap. Either way if never replaced good preventitive medicine. I had a cap that wouldn't hold 15 psi, only like 11, it would cause fluctuations like you mentioned.

 

[SRadke]

I replaced a thermostat in an 06 yesterday that was causing the truck to overheat. Hotter than you have but could be a restriction just the same.

-Scott

 

[AH64ID]

I run 215-220 when pulling a long hill so it could be normal, but most electric fans are only rated for about 18K GCWR if I recall, so you are above that.



I have only ever heard the fan on my manual trans truck once while towing. 90* out, driving 25, 20 mph tail wind, and a steep long winding road, at elevation. I had never worked the truck so hard in 3rd gear.



But radiators do plug and get old and lose efficiancy, if you are worried about it I would probably do a flush, t-stat, radiator replacement. . but it may not drop it any.

 

[TCDiesel]

Electric fans Just cannot move enough air when towing in 70*+ Air temp in stop and good traffic,Pulling long grades will cause the temp to raise,this will also cause warmer auto temps,If You tow regularly in city traffic or climb hills or steep grades "don't install electric fans on tow vehicles" The factory fan will NOT engage until 218*+ and will dis-engage at 32 MPh+.

 

[JBallou]

Sounds like the combination worked before there was a problem. Can you clarify one more time for the doubters?

 

[DMorris]

220 while pulling isn't bad if you know your cooling system is operating properly. I would think one can run up to 235 fairly safe with the proper pressure cap.

Are the fans on a temperature switch and run in auto mode? or are they immediately on with keyswitch power? If they are on a thermostatic switch, what temperature do they cycle on/off? And is it operating correctly?

When the fan is running do you feel strong airflow infront of the radiator/intercooler/condensor assembly?

This is a common area for dirt and road grime to get packed up between the different cores and cause air restriction, leaving you will a poor airflow condition that causes overheating. If your monitor watches IMAT, are you noticing an increase in inlet air temperature?

High torque loading at low rpm can also cause an increase in coolant temps. .

Fans are on a switch. Go on at given temp and stay on until below the given temp. When fans run there is a lot of air being pulled through the radiator,intercooler,condensor units. But I am thinking not enough.

I have replaced the thermostat a while back but think I am going to swap it again.

To answer another question raised, I have been pulling with this truck for years, three changes have been made since the problem began. One is I am pulling a larger fifth wheel trailer ( a good #4000 heavier) . Second, I no longer run the edge juice but a smarty S06. I can change settings on the smarty and it still runs hotter then in the past. Though setting it up on #4 (no timing) and rail pressure one over stock, it does pull much better as far as power goes. ( again thanks Todd at T&C - giving me phone advice on the road to help me get the smarty working better for me).

Third , I have replaced all 6 injectors with new stock injectors.



If this turns into a lack of air going through the radiator, is there a replacement available that will work ? Hate to even ask, went through two stock fan clutch's before I swapped to electrics. Of course I have no fan, no clutch, no shroud nothing but a lighter wallet.

 

[Wingate]

Fans are on a switch. Go on at given temp and stay on until below the given temp. When fans run there is a lot of air being pulled through the radiator,intercooler,condensor units. But I am thinking not enough.

I have replaced the thermostat a while back but think I am going to swap it again.

To answer another question raised, I have been pulling with this truck for years, three changes have been made since the problem began. One is I am pulling a larger fifth wheel trailer ( a good #4000 heavier) . Second, I no longer run the edge juice but a smarty S06. I can change settings on the smarty and it still runs hotter then in the past. Though setting it up on #4 (no timing) and rail pressure one over stock, it does pull much better as far as power goes. ( again thanks Todd at T&C - giving me phone advice on the road to help me get the smarty working better for me).

Third , I have replaced all 6 injectors with new stock injectors.



If this turns into a lack of air going through the radiator, is there a replacement available that will work ? Hate to even ask, went through two stock fan clutch's before I swapped to electrics. Of course I have no fan, no clutch, no shroud nothing but a lighter wallet.

Take a good flashlight and have somebody put it against the back side of the radiator and move it all over the raditor. Watch as its passed along and verify that you see light on the front side all over the radiator.

Another idea is that the extra 4K is helping to exceed the cooling capacity of the electric fan. Is there room on the front side of the cooler stack to add an auxillary smallers pusher fan (or two small pusher fans??) Do you have a pic available of the electric fan setup? And is it covering enough surface area to provide adequate cooling???

 

[AH64ID]

What gear are you pulling the grades in?

 

[DMorris]

5th gear at times. Have a feeling it will be 4th on long grades in the west.

It seems to keep the temp down a little if I dog it a bit and pull 6th instead of down shifting to 5th right away.



Someone mentioned a pusher fan to help ? But then one other person mentioned he tried adding pushers to his pullers and it didnt help ? I would certainly invest in a pusher or two if they would help, but dont want to throw away money if its not going to work.

 

[Wingate]

One issue that you can encounter with electric fans is that if they are direct mounted, they will only pull air thru the cooler infront of where they are mounted. There are some electric fan setups that are more expensive, but they are dual fans that are shroud mounted. By moving the fan up off the cooler and encompassing more of the radiator core, you effectively cool more surface area of the radiator. Surface are is king when it comes to cooling systems. . Thats why a stock clutch fan and shroud works so well.

Pusher fans can help, but they wont if you install then directly infront of the puller fan... they need to be where the existing fan isnt.

 

[DMorris]

My current set up. This was no cheap date.



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This is a Flex-lite ? Set up if I remember correctly .

 

[Wingate]

Looks like a pretty good setup... As long as the shroud is sealed off and making the fan pull all the air THRU the cooler...

Had an ATV that seemed to run hot although everything checked ok... finally bought a new fan motor and realized that the old motor was wearing out and not turning as fast as it once did. . really didn't notice it until I heard the new fan come on... Not saying its your problem. . just something else to check. .

 

[wlowe]

Here is the link to the Flex-a-lite fan that is recommended for your year model. At the bottom of the page it says that it meets the recommended factory GCVW ratings. Unfortuneatly, it looks like you are towing above your GCVW so how well the fan cools is questionable.



03-08 Dodge Cummins Diesel Truck Fan

 

[SRadke]

Seems to me the easy solution is go back to a factory engine driven fan. Problem solved. Sell the electric one to the next poor sucker that thinks it will work.