Had the recall done and its still doing it. I was watching it this evening and on the dash it shows 210 but the ECM is showing it never getting above 194-195 with or without the fans on high. I might just throw a new thermostat in it. I see RA has a GM one that shows 195 and an AC Delco one that shows 190 opening temp. Either one should work, correct?
oem is better. it's actually made my MAHLE for them and is 187deg I believe. and there's always a plus or minus spec for that. there was a thread where I guy bought 5 stats and every one of them opened at a different temp testing them on the stove. aftermarket lower temp ones like the cheap motorad brand are pretty random.
refresh my memory. what is your issue? it sounds like it's working fine? LS engines are funny, they have the thermostat on the cold water side after the radiator before entering the engine but the Temp sensor is in the drivers side head. one of the hottest spots. they mostly run around 195 and cycle around a bit on a scanner. that's the actual exit water temp. the dash doesn't really even matter. but if you look the thermostat is actually a much lower temp. usually about 10deg lower rating. something like 184 or 187, I can't remember right now. and they have a bypass built in to help warm up so the fact that your fans are on and you can get it below the temp is normal. when it's in bypass you could be driving in below zero Temps and still be at 190deg engine Temps while the radiator is freezing up.
if you want to adjust the temperature your fans come on, hptuners will allow you to do this to a point.. there's some hard coded limits to it.. guys run into them trying to put a 160deg stat in the car and the fans won't tune on early enough to match. it's hard coded limit hpt can't over ride. but shouldn't be a issue if you're wanting them to turn on later.
also remember there's a fan table for ac pressures/temp too. so as your high side pressure goes up the fan speed will increase for that. ac high pressure takes priority over coolent temp.
this isn't our trucks, but you get the idea. same basic map in both.
