Engine/Transmission (1994 - 1998) Loud humming noise?

[Elite1]

Once about 3 years ago I had a loud humming noise come from some where in the engine area, seemed like near the firewall but not sure, it lasted about 10 seconds then stopped, while I was at an intersection. Last week I got off the freeway and pulled up to a stop light and heard the exact same loud humming noise, it lasted about 5 seconds then went away... . it almost sounds like a howling, almost like a radiator overheating... . but the truck isn't hot, has good oil pressure etc..... Now today it did it again as I slowed down turning into a farm off a highway, it made the same loud sound, and lasted about 20 seconds. Unfortuanatley the sound goes away before I can get under the hood for a better look. All fluids and gauges check out OK. Any ideas what this could be?

 

[Tardog]

Seems like each time you had been running for a while. I would suggest that it is the fan kicking in. These things run so cool that we don't get to here the fan run very often especially when stopped. Just my couple of pennies worth ?

 

[PUMPERDUDE]

Roger on the fan. You know it when it locks up. Nothing to worry about 1.