On the Road, overheating, help!

[DonTX]

I had a hard day coming from Phoenix to Kingman AZ this afternoon. It is hot out, and I am grossed at 20k.

When I started climbing grades my heat guage would go to the red! I tried several things, turning the heater on full blast helped, and it seemed to be an "airspeed" related problem. If I slowed down, it only heated more! I stopped halfway up one grade to let it cool, idling did not seem to cool, it seemed to want to go hotter.

I found some relief if I could keep up the speed as much as possible, hit the hills as hard as the EGT would allow and the added air flow appeared to help the cooling, of course that kept the transmission locked up and avoided transmission heat into the cooling system as well. Coasting down hill of course cooled it back off. I am thinking maybe fan clutch? It seemed to get worse as the day wore on, even fairly level pulling was getting more heat showing on the guage than I wanted. I cannot recall ever having any overheating problems before this.

Suggestions anybody?

 

[Wiredawg]

First, you can check the fan clutch while hot, shut down. if it free wheels, its bad. Could be sticking thermostat. Check collant color. When did you change coolant last? How does the radiator look. If it's clogging it can have huge impact on cooling. Maybe radiator fins clogged affecting airflow. A carwash could help if it is. No different color smoke like head gasket and cooalant leak?



This is all I can think of. Let us know what you find



Wiredawg

 

[JCasper]

First, you can check the fan clutch while hot, shut down. if it free wheels, its bad. Could be sticking thermostat. Check collant color. When did you change coolant last? How does the radiator look. If it's clogging it can have huge impact on cooling. Maybe radiator fins clogged affecting airflow. A carwash could help if it is. No different color smoke like head gasket and cooalant leak?



This is all I can think of. Let us know what you find



Wiredawg

I was gonna say the exact same things.



Someone on a local forum here just had the same problem and it was a very dirty radiator.

 

[B.G. Smith]

Sounds like air flow since it runs cooler at higher speeds. I think if the belt is old it can slip on the water pump since it is turned by the back side of belt???. bg

 

[MMeier]

I'd say fan clutch or t stat possibly. Where are you headed to Don?

 

[DonTX]

I will be coming from Kingman to Las Vegas tomorrow. Will stay at American Campgrounds 3440 N Las Vegas Blvd for a night or so. Thanks for the hints guys, will check them out more. I had intended to check the fan clutch when it was hot but forgot. I opened the hood when I got parked and the fan seemed to be blowing lots of hot air. I got a window screen in front of the radiator for bugs, might take it out to aid airflow some. No exhaust indications of problems - yet! Sure don't like that heat guage going that far over there!

 

[jelag]

I've had several of my trucks across the desert from Phoenix to LA or San Diego in 112* - 115* pulling a 20 K lb trailer. .

We would see the temp gauge straight up across the desert and it would climb up to the center of the second 0 in 200, or just to the end of the 200... never farther... . with the AC running...

We would see a higher than that temperature if we tried to follow another vehicle closer than say 100 ft... . we only assumed that the draft of the air from the front vehicle pushed too much of the air around our truck and not through the radiator and engine...

I agree with the above posts...

After re-reading the above I should say that our 04 with 225K miles and a stock engine including the belt leads me to believe you might look someplace else...

I was taught early on to try and turn the alternator with your hand when the engine is stopped. . either grab the pulley or push the fan on the alternator. . if you can twist the alternator without the belt moving the belt is too loose... .

I'm guessing a bad fan clutch... . I might add... I assume that you've checked the water... . With several of these trucks and lots and lots of miles... we've never seen a bad thermostat... not that it can't happen...

Good luck...

 

[MMeier]

Don ,keep in mind if you want to cross Hoover Dam, they have a checkpoint to go through in which they will want to look all through your 5'er, if thats what you have behind you. Kind of a PITA, if you don't want to do that, turn on Hwy 68 just north of Kingman and come up through Laughlin/ Bullhead City that way. Couple of moderate hills on that route.

 

[JCasper]

Don ,keep in mind if you want to cross Hoover Dam, they have a checkpoint to go through in which they will want to look all through your 5'er, if thats what you have behind you. Kind of a PITA, if you don't want to do that, turn on Hwy 68 just north of Kingman and come up through Laughlin/ Bullhead City that way. Couple of moderate hills on that route.

I came through that checkpoint in May and it was no big deal.



It was not very busy and he only looked for a couple minutes and sent me on my way.

 

[MMeier]

What day of the week did you go through? Most Fridays, if you do not get through there by early afternoon, it can back up quite aways with all the crazy Az. folk coming here to part with their $$$$ for the weekend.

 

[JCasper]

What day of the week did you go through? Most Fridays, if you do not get through there by early afternoon, it can back up quite aways with all the crazy Az. folk coming here to part with their $$$$ for the weekend.

Good point. I came through on a Tuesday I think.

 

[DonTX]

Thanks again, I had been meaning to check on current Hoover policies, I think I will bypass it.

When hot, how much resistance should the fan clutch provide? Since I have never tried to spin mine when hot, I have nothing to judge by. I assume there is still the ability to turn the fan even when hot? I am still thinking strongly that the fan clutch is causing my problems.

 

[JCasper]

Thanks again, I had been meaning to check on current Hoover policies, I think I will bypass it.

When hot, how much resistance should the fan clutch provide? Since I have never tried to spin mine when hot, I have nothing to judge by. I assume there is still the ability to turn the fan even when hot? I am still thinking strongly that the fan clutch is causing my problems.

IDK how much resistance as I have never tried to turn mine when hot either.





I do know that on a hot day after hard pulling if I walk around to the front of the truck while it's running I can definitely here the fan sucking air. It is very noticeable compared to what you hear with normal temps.

 

[jjdiesel]

radiator

I experienced the same thing on a trip through Colorado... . did everything, well, almost. Changed thermostat, no change. Changed out the fan clutch, no go. Cleaned off the radiator... (which was next to impossible to see) and bingo!... fixed the problem. The easiest thing to do was the last thing I did... . duhhh, lesson learned. A flashlight between the radiator and the AC revealed the dirt... surprising how little (dirt) it takes to create such a problem. Anyway... hope you get it fixed up

 

[DonTX]

Yeah, most everything I have owned made a noticeable noise when engaged, something that seems lacking, cannot recall I have ever heard it kick in, but it never ran over mid range either. . I am going to go out and hose down the radiator this morning just in case dirt in the air passages is causing it.

IDK how much resistance as I have never tried to turn mine when hot either.





I do know that on a hot day after hard pulling if I walk around to the front of the truck while it's running I can definitely here the fan sucking air. It is very noticeable compared to what you hear with normal temps.

 

[RVTRKN]

I had a 94 2500HD 5. 9 gasser that started doing that at 90K on the odometer, when my water pump started leaking I found a bad clutch fan when I replaced it. I did look at the clutch fan and thought it was OK because of the air that seemed to be blowing from the fan when I opened the hood. I washed down the radiator changed the belt, tensioner and flushed the system with negative results.



The funny part was before I found it, I had bought a V10 radiator and all the necessary parts for converting over to the larger system. I didn't mind it too much, due to the fact it always ran hot when towing, even when it was new.

 

[LandShark]

Did you remove the window screen? My guess is that it would block about 1/3 of the air flow.

 

[JCasper]

Yeah, most everything I have owned made a noticeable noise when engaged, something that seems lacking, cannot recall I have ever heard it kick in, but it never ran over mid range either. . I am going to go out and hose down the radiator this morning just in case dirt in the air passages is causing it.

When I heard mine I think I was down in Death valley, it was 108* that day.

 

[TAbbott]

Theres a product called "Diesel Water Wetter" that's put out by Red Line Oil. You can find it at most NAPA stores and other parts houses. You add it to your coolant and it seems to help keep the temps in line.



Hows your Fifth Airborne working out Don? Have you tried adjusting it one way or the other from the line on the shock or does it seem to work best right at the line?

 

[oneshotkyle]

if i had a heating problem i wouldn't drop down into laughlin nevada and then back up that grade. unless you got something that you don't want to go through an inspection. take the hoover damn if at all possible and avoid another big grade.
find a garden hose and flush as much dirt and bugs out as possible. there is alot of restriction for air to go through (condeser, intercooler then radiator). try the easy stuff first.