Engine/Transmission (1998.5 - 2002) Overheat, why?

[DWest]

Last week pulling 5000 lbs east on I80 coming out of Laramie my truck went to 230 degrees just like that. I was pulling in third at 75 so I had plenty of rpm's going up a 6% slope for 6 miles. The fan clutch never locked up and repeated the same problem back home pulling my skid loader yesterday. Do I start with the thermostat or go to the dealer and get the fan clutch replaced? Also is the fan clutch covered under the engine warranty or not? The truck defueled at 230 degrees. DW@

 

[OTRPU]

Don't know nothing about your warranty questions, never had one, prolly never will. I pull that stretch all the time both loaded and MT. I run in OD locked in cruise at 65, when it drops out of cruise is my signal to turn OD off. Engine temp never been over 200 since having new fan clutch and radiator installed. I keep the aFe filter clean and same with the fuel filter. I'm not a very fast driver, like 2,000 revs MT, GPS indicates bout 72 MPH, loaded I rarely exceed 65. Fuel is killing me so I try and get as far as I can on a gal. My transmission temp runs cool on the road loaded or not usually half way tween left side mark and 150. Goes to 180 stop'n'go through the city traffic. Both coolant and transmission temps are scary cool driving on the road seems to me. If you're a heatin seems somethings plugged or not sensing right.



Cheers,

Steve J

 

[DWest]

What causes the fan clutch to engage, is there a heat sensor on the clutch that locks it up? Does it have anything to do with the water temp after the stat? DW

 

[A Ingalls]

West Im having the same problem, I live in colorado and every place I go I end up going over a pass. I pull a 30ft 5th wheel and have always had abit of a problem with heating up. it runs about 170 to 180 on the level in drive or overdrive. I took it to the dealer last spring to get the fan clutch looked at they said it never had worked in its life they installed a new one but it did'nt change my problem as I never heard the new one kick in either. I took it back to the dealer they checked it out on thier computer and said it shows that its fine. Si i'm wondering what to do next. One thing you need to do West is to make sure the front of your radiator is clean as dirt and things like cotton wood fuzz can get sucked in there even thou the front can look clean just look down from the top between your radator and the aircooler. I blew my radiator out and helped some. I don' think its your stat or you would have problems at othe time's I believe. Hope you get your problem fixed. let me know if you do. thanks A Ingalls -- email address removed --

 

[A Ingalls]

{Over heat, why}

DW Im having the same problem. I live at 9000 ft. in Colorado and every place I go I have to go over a pass. I have always had a heating problem and fianlly tool my 98 24 valve to the dealer her in Silverthorne. they checked out my fanclutch and said that it never had worked so they installed a new one this spring well im still having heating problems and I have still not heard my fanclutch come in I took it back to the dealer and they are saying the new one checks out as working but did'nt offer any solution I guess I'll take it to a cummingss dealer and see what they say

Dw. One thing I've heard is that you should make sure that your ratiator is not pluged or the heat won't go though the radiator to the sensor on the Fan clutch. Look down between the radiator and the air cooler and you may have some trash collected inthere I had some in mine and it did help some to clean it. I believe if your stat was bad It would bother at other times. Hope you find your problem. A Ingalls -- email address removed --

 

[Big A]

Pull the radiator out, and power wash it. that did it for me. Make sure you don't hurt the fins.

Big A

 

[A Ingalls]

Thanks for the imfo, Big A. I believe I will try that next spring when I hook up to my 5th wheel again. Noticed that you have a 4" exsaust I had one installed also but every since I have a quite abit of lag before the turbo picks up also a lot of black smoke I am going to try a better and bigger air intake filter system that should help some I don't want to spend the money for a bigger turbo right now. If any one has an idea I would appriciate hearing from you. A Ingalls

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98. 5 edge, tripplelock C. westack guages, airbags, airbaghitch, pacbrake 4"exsaust Sunnybrook 5th

 

[Snow man]

The rad is likely plugged from the breather bottle spewing oil mist all over the fan. It needs a good cleaning/degreasing/powerwash. Reroute/extend the breather under the truck while your at it,so it dont happen again.

 

[Big A]

The automatics have a little more lag than the manuals. I have no lag. I also run the stock air box, and filter. You may want to adjust your transmission commander(if you have one), so it does not lock up so soon. Early lockup will cause lag.

Big A