Engine/Transmission (1994 - 1998) Got Hot!

[rickandcheryl]

How do you guys keep your engines cool? I'm talking about water temp. This last weekend, towing my 5th wheel up a pretty steep winding road (could only do 30-35MPH because of the road) I about pegged the water temp and the trans gage ran up to almost 230 degrees! Had to stop three times and cool things down. Could I have a bad fan clutch? What about a Horton Fan, are these any good and would it help in this situation? Thanks for your input, Rick

 

[Bob Wagner]

Rick, could you hear the fan clutch engage?

 

[Garry Verheyden]

Rick,

I no longer worry about my water temps. too much. Maybe I'm too over confident for my own good now. Last year I was towing my 15000# 5th wheel through the Mojave desert, it was a heat spell and it was 120-125 degrees out. At 65mph I'd put my hand out the window and it almost hurt. It felt like holding a hot blowdryer on my hand. We had the air conditioning on at the max. We then went over the pass between Palm Springs and San Diego (can't remember the name) The water temp. Gage was at the max, past the red line. I was quite nervous as I saw a water fill station Avery 1/4 mile for 15 miles. I knew the potential for overheating was very high on this hill.

I dropped down to third gear to keep the revs. up hoping the clutch fan would drop my temps. No matter how low my egts. were kept and what rpm I was at, I could't get my water temps. to come down. After 10 mins. of driving, I said the heck with it, I have lots of fresh water in the 5th wheel and the tools to fix it. Let it blow. We accelerated back up to 60mph in 4th gear and watched the water temps. go further off the scale than ever before. To our amasement everything was fine. We passed quite a few cars(whithout trailers) and counted 22 (YES 22!) cars that were overheated at the various water fill up stations, and we didn't blow any hoses with all our weight. Obviously,I also had luck on my side that day.

Garry.

 

[Eric_77]

There was some discussion on this same issue in the hauling section here is link

 

[rickandcheryl]

Bob, would I hear the fan engage? Don't think I heard it, but not sure. How can I tell if it is engaging or how do you test the fan clutch? Thanks, Rick

 

[Bob Wagner]

fan clutch

Rick, When the fan clutch engages you will know it because it REALLY HOWLS and the temps drop

 

[Dieselnerd]

Rick, ditto on the fan clutch. I've towed up some long grades in Nevada with about 13K of trailer behind in the heat. My fan engages right about midpoint on the gauge and like Bob said, you can hear it roar even above the diesel clatter. The hottest mine ever got was about midway between the center and the red mark. Clutch engagement depends on air reaching the bi-metal valve actuator in the clutch. Tailwinds, dirt in the radiator or anything else that keeps the air from reaching the clutch can cause delayed engagement. Naturally the clutch can also be bad. With a cold engine there should be some resistance when you spin the fan by hand. If it spins freely it's probably bad.

 

[PHaller]

If it's hot out and you are only doing 35 mph up hill your TC is unlocked and generating a LOT of heat when towing in 2nd. That heat generated by the TC is tranfered to the water to oil transmission cooler. I know... I tow a heavy 5er with an auto too. < Never again!> Is your auto temp sensor in the pan? If it is, you are reading the cooled oil in the pan... the output from your TC to the water to oil cooler is closer to 320 degrees. If that's the case, you'll overheat the water. You need a TC lock up switch in 2nd and 3rd to prevent this from happining. That means an after market valve body capable of lock up in 2nd and 3rd. Check a vendor of your choise for this.

Unlocked TCs generate heat because they shear fluid in fluid coupling. When they are locked and pulling there is almost no heat. Going downhill in 2nd or 3rd or even in overdrive the TC is also in unlocked mode and temps will continue to rise, again, because of the TC shearing fluid. Get yourself a lock up switch and lock the TC when towing.

Your truck is fine and the fan is working fine too. It's your transmission generating all that heat.

-Paul R. Haller-

 

[DEZLPWR]

Dumb question.....

Do only the Autos have a fan clutch, or do the manuals have one as well? I have an NV 4500 and have never heard mine & I have never hit over 190 degrees... .

 

[Garry Verheyden]

They all have fan clutches, and you'll definately hear them when they engage( unless your hearing is like my dads,he can't hear it)

Garry.

 

[DEZLPWR]

Either mine's bad, or my engine is just not getting hot enough... . What temperature does the engine have to reach before it kicks on? Mine has never been hotter than 190 degrees. Does that mean the fan clutch has been on and doing it's job & I am deaf, or it has not been hot enough to come on???

 

[RHARVEY]

I just istalled a new clutch fan and then pulled my 9k 5er in 102* weather up and down 5% grades. About 200* I heard the jet engine under the hood. And at that point it was if the needle was nailed to the guage... it never moved any higher.....



Rick

 

[DEZLPWR]

Thanks Rick....

I guess I'm not working the Cummins hard enough!

 

[rickandcheryl]

Rick, where did you get the replacement fan clutch and what did it cost? I really think mine is bad, never heard any increase in sound under the hood and the temp gage was almost pegged at 230 degrees. Thanks, Rick

 

[M Barnett]

Go and read my post from last week about cleaning the outside of your radiator.

Michael