03 2500 Hd Temp Issue

jlittle · July 19, 2008

I have an 03 2500 HD 4x4 6.0 with 120k miles. Last week while pulling my horse trailer loaded the temp guage went up over 210 for the first time ever. checked fan clutch and it was worn so replaced. Left next morning and when really getting on it temp rose to over 210 again but would go back to 190. During this time I never could hear the fan clutch engage. Today pulling trailer temp got up to about 225. Manual says "normal" operating temp is upto 250. Should I be worried? Used to I could hear the fan engage if temp rose to 210 and it immediatly went down to 190. when it is getting this warm the tranny temp is just over 200. Any help would be appreciated? Could it be a failing water pump or thermostat?

Killerbee · July 19, 2008

I have an 03 2500 HD 4x4 6.0 with 120k miles. Last week while pulling my horse trailer loaded the temp guage went up over 210 for the first time ever. checked fan clutch and it was worn so replaced. Left next morning and when really getting on it temp rose to over 210 again but would go back to 190. During this time I never could hear the fan clutch engage. Today pulling trailer temp got up to about 225. Manual says "normal" operating temp is upto 250. Should I be worried? Used to I could hear the fan engage if temp rose to 210 and it immediatly went down to 190. when it is getting this warm the tranny temp is just over 200. Any help would be appreciated? Could it be a failing water pump or thermostat?

I would worry if you get to 230 and it still has not come on. You should be hearing it briefly on cold starts.

dewfpo · July 19, 2008

My fan always roars on cold starts and for the first 5 or so minutes, then it's perfectly quiet until needed again. Does the engine still have the original coolant thermostat?

DEWPFO

Kodiak450 · July 20, 2008

There's a revised thermostat for the fan, I have the same truck in same year and had this issue always when I pt the plow on and drove X amount of miles. I also bought this stuff called "water wetter" which is suppose to help you run cooler, so I am running slightly under 210 I think? What ever the middle gauge says. Anyway this revised thermostat, after installed took care of the running hot issue and is a very easy install. I did a search on Google and found a forum where they listed the new part number and it is also on the service bulliten for GM. Hope that helps..