Engine/Transmission (1998.5 - 2002) Fan clutch

[cmills]

I have a 99 24 valve, and have never heard the fan engage, like when I had my snow plow on and it got pretty warm out I looked down and the temp was climbing, I figured it would come on real soon and it never did and I had a heck of a time getting it cooled down. I was curious if maybe it did come on but was just to quiete to hear and to warm to cool it down so I went and put the plow on my dads 97 12 valve and when it got warm the fan engaged and it sounded like a jet and the temp dropped immediatly, so I guess my question is, Is there some kind of difference between the 24 and 12 valve which would cause this (highly unlikely and probably a dumb ?) or is my clutch just bad. It is not loose and there is no fluid leaking from it. Also in the morning when you first drive dads truck it is real loud like the fan is engaged, mine is not like that. I checked and the fan does have quite a bit of resistance when you try to spin it right after you shut the truck off and it is still hot. So is it bad or not? If so and I need to replace it, is it very hard to do or is it pretty simple.



Sorry this is so drawn out. Any help would be greatly appreciated!



Thanks,

Cory

 

[Seed Guy]

Diesels are really hard to heat up and mine drops temp fast when the fan engages i would check out everything that could cause it not to engage. Or even thermostat?

 

[RJ2]

It was so hot in tampa today it was coming on alot.

 

[illflem]

12 and 24 valve clutch is the same

How hot is too hot? My 12 valve fan has only come on a handful of times since '95, temp got up to around 210 before it roared, almost instantly dropped to 190 and never came back up, fan has only been engaged for about 30 seconds max. First time I was worried that it wasn't going to come on when the temp started climbing, it's never made it into the red though.

 

[juicedcummins]

I had trouble with my 99 also. If you haven't changed out the origanal t-stat there is a real good chance that it is the culprit. There was a bad batch of t- stats in most of the 99's. They didn't let enough water throug to warm up the rad and in turn heat up the air going though it to trigger the fan clutch untill they are real hot.

 

[cmills]

which thermostat

I went and looked at the tsb's for cooling and there is a tsb for changing the thermostat if your esn is 56512007 or prior mine is later than that, so does this mean my thermostat is okay or should I change it anyway? I have never had a problem with the truck getting hot when pulling even in the summer just with the plow on was the only time, it seems to stay a little above 190 when pulling. If I do need to replace it does anybody have a cummins part number.



Thanks, Cory

 

[RJ2]

I always told my wife it was hotter in Tampa than in Daytona. When traveling to Tampa it came on the first time and I did not know what was going on. I thought the transmission was going. Came back to Daytona and never heard it again till I went back to Tampa. Now that I am living here I notice that driving around town or if it has been setting in a parking lot for awhile

it will come on for a short period. The temperature here is just enough to kick it on and that is my proof to the wife that there is no question about it being hotter over here.

 

[RustyJC]

Re: which thermostat

Originally posted by cmills

I have never had a problem with the truck getting hot when pulling even in the summer just with the plow on was the only time, it seems to stay a little above 190 when pulling.

Cory,



My truck came with the 190 degF thermostat. Pulling our 5ver (21,180 GCW versus 21,500 GCWR), it consistently runs 195 degF (about a needle width above the 190 degF mark). When not towing, it will run around 185 degF. The fan clutch will cycle occasionally, more often during hot weather (as you would expect) when towing.



Rusty

 

[mberry]

I just changed my thermostat yesterday to a 180. Keeps the engine much cooler in the summertime driving through the hills around here.

 

[cmills]

just changed it

Put in a new 180* thermostat today a the engine seems to run about 10* cooler but the old t-stat was a 180* also I don't know why it is running a little cooler but it is. I also put on a new fan clutch from NAPA, I can hear this one going a lot more when I first start it and take off, I put my snow plow on today and ran it with it on and it still would get hot (225*) it did however take longer I'm not sure whether the fan was working right or not but whatever the case it would not be able to cool it down. The temp was almost 60* out side, so do you think it is working right and it was just to warm out and not getting enough air to cool it with the plow blocking a considerable amout of air or is it still not right?



Some information very soon would be very helpful as I am going to Kansas this Friday to haul a car back to Indiana,although I doubt I will have any problems with a full radiator of air.



Thanks,

Cory

 

[rashwor]

My '99 does the same...

thing. The hottest I have every gotten it has been around 195*, but the fan never kicked in. I know what they sound like because the one on my '92 will kick in when it is really hot and the temperature gauge swings back to cold so fast it nearly breaks off the needle on the cold peg!



I have never changed my therostat, but I will when I change the coolant this summer... it is on my to-do list. I would really prefer it to stay 190* or lower on the gauge when running empty. Oo.

 

[kaffine krazed]

Check the radiator see if the air passages are plugged with dirt. Also check to see if the upper radiator hose and radiator are getting hot.



To check the fan clutch when the truck is hot open the hood rev the eninge up to 1500 rpm and shut it off while watching the fan it should stop with the engine if it continues to spin either the fan clutch is bad or for some reason the fan clutch isn't getting hot enough to engage.

 

[cmills]

I do keep the radiator blown out,so I said heck with it and ordered a clutch from dodge today and am going to take the NAPA one back, I told them it wasn't working and they said OK, (if it is working it isn't working quite right) I did notice that the clutch I got from NAPA isn't quite as big as the original one. I think that might be why it works but not quite as good as the original.



To my suprise the Dodge clutch was only $16 more :--)



Rashwor, the part number for a 180* t-stat from cummins is 3954194, it cost me right at $20.



Cory