Engine/Transmission (1994 - 1998) How often does your fan kick on

[ndurbin]

My engine fan has been kicking on and off quite often recently. It doesn't start to kick on until the truck reachs 160* or so on the guage. It'll stay on for about 3-4 min. then kick off for about 2 min. and kick back on. It does this repeatedly until I shut the truck off.



Thanks in advance

Nathan

 

[CMartin]

I just got my CTD lastnite... FINALLY... . anyway, I was going to post the same question. My fan is on ALL the time and gets kind of annoying. Maybe the clutch is gone out?

 

[mikel]

I don't know if it's a problem or not, but mine does this annoying nonsense too. I can't see any reason at all that the fan clutch should be coming on when running down the freeway empty. I mean seriously, I'm going 70+mph how much more airflow is the fan going to provide over the 70mph ram-air?



It's on my list of things to replace a little later just to see if it actually is bad.



Mike

 

[fortunate1]

Your fan is coming on too much, too soon. The fan will spin even when things are cool because of the fan clutch, but it's slipping until the temp rises enough to lock the clutch up. When the fan clutch locks up, the fan will spin at the same rpm as the clutch hub. You'll definitely know when that happens because it sounds like a jet engine just went to full thrust under your hood. On some summertime trips from VA to FL on I-95, my fan clutch locked for a couple minutes about 3 or 4 times during an entire one-way trip. Outside temps were at 100+ deg during these trips. The fan didn't come on & off repeatedly like you reported. If the clutch doesn't function as it should (locks too much or not at all), you should replace it.

 

[Todd G]

How do you test for a locked up fan clutch? I think mines been locked up since 1995. I've never heard it come on even in 120 degree weather. I've tested car clutches by rolling up a newspaper and stopping the fan if the engines cold, but I want to keep my extremities with the Cummins

 

[DavidGardner]

The only time mine ever came on was while pulling a 7 mile grade with loaded 26 ft trv trl. It was a very steep grade and I was stuck behinde a motor home @ 20 to 30 mph. I had to shift down and lock in 2 ond and 3rd gear. It was very noticeble like some one said a jet engine sound. I have since been in Yuma Az in the summer time with 115 degree heat with a fully loaded 2 axel trlr. with it never comming on. The temp guage never got above 165 degrees. The radiator on these things are huge. Mine is a 95 with ovewr 170,000 miles. I dont think you will over heat it but you might have the fan thermostat checked.

let us know what you find.

Dave Gardner.

 

[Deezul1]

I have never heard mine come on and I have replaced it once. Maybe some one like me can trade off with one of the ones that comes on a lot and see what happens. Where is Sealy, Texas? How far from Waco?

 

[CMartin]

Well, for what it is worth I replaced mine today. I can actually feel a difference in the acceleration of the engine. It comes up to 3K rpm much quicker than it did yesterday. Maybe I am wrong, but it sure seems like it. One thing that is for sure though is the fact that I no longer hear the fan and my clutch was locked up solid!

 

[y-knot]

It is kind of hard to always know when it locks up and engages, but generally it stays off while driving on the highway, and open road. Comes on after you inter town or city traffic.

 

[jtwcummins]

Mine locks at about 180* in town and the same on the hiway. If I am not towing uphill the engine never gets to 180 on the road.