Engine/Transmission (1998.5 - 2002) My 2001 HO is over heating!

[brobeson]

My truck started to get hot every time I went up a hill while pulling a trailer (wide open in 6th).



So I checked the thermostat and sure enough, it was bad, it busted.



It also gets hot if I let it idle to long.



So I replace it with a 180% unit for a 1999 as per Cummins suggestion. It now runs at about 180 % until I go up hill. (Wide open in 6th).



So I gutted the old therm and now the truck runs cooler except when I go up hill while towing. (Wide open in 6th).



Been to 2 dealers, one said maybe the fan clutch has gone bad, as I can still hear the fan come on about 190%. He thinks it just may be slipping. But I read where many people have removed their fans, have they had a over heat condition?



The coolant was changed in March 2002.



Anyone have any ideas as to what to look at or try next.



TIA



Bob

 

[mbrolin]

I have a 01 2500 4x4 pulling a 5er with a GCVW of close to 18,000lbs. We just got back from a 4600 mile trip. Even pulling hills in 102deg heat my temp never went above the 0 mark on the 190deg reading. It stayed just about centered between the 9 an 0 most of the time. I would suspect the clutch fan as well. In fact the EGTs stayed about 6-700 degs most of the time as well. This trip was through Oregon,southern Idaho,Montana,Wyoming,South Dakota and eastern Washington.

 

[GeneralMachine]

Engine run's hot

Hey Bob I was wondring if you have checked to see if maybe you could have some blockage of airflow? Also a air restriction will make the engine overheat. when the engine is good and hot if you shut it down how stiff is the fan clutch? Do you have a heat gun, for maybe the gage is off. sometime's it's the simple thing's that can take us off corse, hope you figure it out. Harv

 

[brobeson]

I tow RV's 2.

This over heating problem just started this trip.



Like your ithas always stayed right around the 190 mark untill now.



The only way to keep the temp down is to start down sifting so I can only use about 1/2 throttle.



I have gotten all the way down to 3rd at about 24 mph to keep the needle from going over the top (white) mark.



Bob

 

[JHansen]

Have you moved your crankcase overflow bottle Bob? The mist that barfed out of mine got pulled in between the rad and aftercooler and promptly attracted every dust molecule in the country-choking off a ton of airflow and raising temps when I work the truck hard. Something to check-there's enough room to look down between the 2 and have a look... ...



Jason

 

[Jim Brewer]

Originally posted by brobeson

My truck started to get hot every time I went up a hill while pulling a trailer (wide open in 6th).



So I checked the thermostat and sure enough, it was bad, it busted.

I am having the same problems, so I decided to replace both the fan clutch and the thermostat. I got both from Fulton Motor Company aka Dodge Diesel Parts. They showed up in 3 days via USPS priority mail. Oo.



On the advise of others, I bought the 1 7/16" open end before starting. They say a picture is worth 1K words, so here's a picture of the new fan clutch with the wrench positioned for it . .



#ad




The thread is a left hand thread . . so you need to turn it clockwise (when facing the truck from the front). I held the pulley in place with an oil filter vice grip plier and whacked on the wrench with a 3lb. hammer. It came right loose.



#ad




You don't have to take the fan off of the clutch before removing it . . it will come out of the top if you rotate the hoseclamp a little for clearance . .



#ad




Once out, there are 4 12mm screws holding the fan on. It's a pretty simple operation to remove them and replace everything the same way it came apart.



I did have trouble getting the threads started for the new fan clutch, so be patient and keep trying.



Next I took out the thermostat to check it and . . low and behold . . it was busted...



#ad




The new one is on the right. There is no gasket, just an o-ring so replacement is *really* simple. I'm going to go test the truck out in a few minutes, but I'm pretty sure this was my problem.



The new fan clutch probably wasn't necessary, but I'm not going to cry about it if the motor runs cool now.

 

[jcbrown]

Re: Re: My 2001 HO is over heating!

Originally posted by Jim Brewer

On the advise of others, I bought the 1 7/16" open end before starting.

Correct wrench size is 36mm.

 

[dresslered]

The fan clutch should be quite easy to diagnose. As soon as my needle touches 190, it sounds like a helicopter taking off. Mike Clay (Claymike) had this same problem with his 2001, and I can't quite remember what it was--I think that the radiator fins were full of bugs/dirt. Might want to shoot him a PM.

 

[Jim Brewer]

Re: Re: Re: My 2001 HO is over heating!

Originally posted by jcbrown

Correct wrench size is 36mm.

Unfortunately, my local Sears shop doesn't carry a 36mm open end, nor a 36mm crows foot (I looked).

 

[PKleine]

Originally posted by Michael Brolin

I have a 01 2500 4x4 pulling a 5er with a GCVW of close to 18,000lbs. We just got back from a 4600 mile trip. Even pulling hills in 102deg heat my temp never went above the 0 mark on the 190deg reading. It stayed just about centered between the 9 an 0 most of the time. I would suspect the clutch fan as well. In fact the EGTs stayed about 6-700 degs most of the time as well. This trip was through Oregon,southern Idaho,Montana,Wyoming,South Dakota and eastern Washington.

Mike,



Mine runs like your does for the coolent temp. EGT's are different story; running down the road empty 65-70 mph in 6th I'm seeing 750-850 pre turbo on the egt. Are my EGT's too high for the loading?



PK

 

[Jim Brewer]

Originally posted by dresslered

The fan clutch should be quite easy to diagnose.

You're right. What I did was block off the radiator w/cardboard and drove around until the needle was just a little above 190. Then I pulled over, removed the cardboard and drove for another block (so that the heat from the radiator would get to the fan clutch thermostat (the coiled metallic strip in the front of it)).



I didn't get the ROAR that I'd heard before when I knew it was working, so I pulled over again, stopped the motor and saw how much resistance there was on the fan clutch by trying to turn the fan by hand. It was as easy for the fan to freewheel as it was when it was cold. Therefore, I concluded that the fan clutch wasn't engaging at temperatures >200 deg F. and probably was in need of replacement.



What I didn't do was mount a thermocouple inside of the fan shroud and measure the temperature going to the fan clutch thermostat. I assumed that if the engine temp was >200 deg F and had air going through the radiator onto the fan clutch for a little more than a minute, it should engage.



Maybe I was wrong and I replaced a perfectly good fan clutch, but at this point all I care is that the motor doesn't overheat.

 

[jcbrown]

Re: Re: Re: Re: My 2001 HO is over heating!

Originally posted by Jim Brewer

Unfortunately, my local Sears shop doesn't carry a 36mm open end, nor a 36mm crows foot (I looked).

Wrench is available at NAPA (or can be ordered).

 

[WestTN]

The design temperature for the 2001 model year fan clutch is 206 degrees Fahrenheit. The other years are probably the same, but I don't know that.

 

[Jim Brewer]

Re: Re: Re: Re: Re: My 2001 HO is over heating!

Originally posted by jcbrown

Wrench is available at NAPA (or can be ordered)

Oops, silly me I posted the wrong picture ... here's the right one . .



#ad

 

[rubberneck]

this has happened to me

My truck did this and 2 others i have worked on. PUll the radiator out and steamclean or pressure wash it. You will be amazed at how much grease and gunk is built up due to the stupid overflow bottle. Mine was plugged solid on about 25% of the radiator surface, and no you can not tell untill you get it out. I pressure wash my engine compartment quite often and when in the truck it looked great. Running empty, no problem but start to pull a load in the heat and bam right on up the needle goes. I have to give credit to Brandon for turning me on to this. He told me to do it and i told him he was full of s**t cause my truck was too clean. Well I ended up eating my words on this one. It only takes a little while to do. It cured my problem, try it you might be surprised.

 

[Midnite]

Re: Re: Re: Re: Re: Re: My 2001 HO is over heating!

Originally posted by Jim Brewer

Oops, silly me I posted the wrong picture ... here's the right one . .



#ad

That's funny!



Mike

 

[benhall]

How often should the radiator be removed and cleaned out? I am in a very dusty location here in oklahoma



Thanks,



Ben