Canadian Hummer Club Forums

The fan clutch doesn't seem to be seizing as I'm able to move the fan without too much resistance. I'll try the coolant flush and tstat change. The temp hovers around 200 and I see the Guage drop to about 180ish and then 200 again. My other vehicles are steady at the mid mark and doesn't change at all no matter how hard I drive or ac running at max

Mine was running a bit warm last year after some work including a new fan/shroud/clutch install and would cycle on temp also. (210ish to 190ish) 
 
The new fan clutch was NFG. It was replaced under warranty and this solved my issue. In the meantime I changed the T-stats and added the Scanguage which made no difference in the fluctuations. 
I never spun the fan so I don't know if it was loose or tight but the Tech who replaced it said it was not right. Since the 2nd one has been put in the fluctuations have gone away.
Granted it is much easier to change the T-stat than the fan. So..for sure not a bad place to start.

Just for laughs and kicks I bought red line water wetter, just poured into my slightly foamy over flow ( I'm sure you all can figure that one) and will see if any cooler,....

Yes Monk let us know if you see a difference in temp. I am running Evans Waterless at 0 psi, so between that and the intercooler now in the new stack, I am running a few degrees warmer than last year. I changed and added so much stuff it is difficult to assign the changes in temp to one thing.
 
D

Just out of curiosity, at what temperature does the engine fan turn on? It seemed like today it didn't turn on and I was running close to 210. So I guess all the cooling was being done by the coolant. Maybe that's my problem of running a bit hot?? Is there a sensor that triggers the fan to turn on? Pics??

Ya you should have heard the fan.... It is controlled thermostatically by the clutch assembly on the fan. Not serviceable but not expensive either. A bit challenging to change but can be done.