On a 75 degree day my new Duramax will get up about 210 degrees on a climb. Is this normal? As soon as I reach the peak it will level off to around 180. Anything to be concerned about? What degree thermostat is in the Duramax?

What is the reason that the cooling fans on the Dmax engines come on all the time. I have an 2004gmc and it will come on when the thing is cold for about a mile. I think this is ok, but LAST fall, pulling my 7800# trailer, it would come on after pulling on highway, and turning on to a side ROAD. Is this the way they are supposed to work. Engine temp was not even 210, and the tranny temp was not even 150. Dealer checked out and said no problem. This is kind of annoying.

Am planning on an extended trip over the mountains this summer, and don't want to hear that fan all the time, but if that is the way it works, so be it.


TANKS.:help:

Are you saying "that" is the reason the fans come on or did you mean to write "what"?

lotto38,
You from Findlay? I grew up there. Live in Fremont now. Got my truck at LaRiche. I think your a tad older than me though.

jlairy,

The dmax t-stat's are 2 stage units. I believe the optimum temp is 207°F. If there is no load on engine, temp will drift down to about 185-187°F

Thanks Dave: I guess running around 210 up a long grade is normal then. And you're right, normal driving is around 180-185.