What's the deal, new 180* thermostat, temp same

[1999GMCZ-71]

Installed a new 180* Hypertech thermostat, and the temp gauge still reads about 200+*. Why is this? Anybody else have this problem?

[robsawatsky]

Assuming that your temperature gauge is actually reading accurately, the thermostat only determines when the flow through the RAD is opened up. If the heat from your engine under the load your observing, ambient temperature, air flow through rad, A/C condensor heat back into the RAD, exceed what can be dissipated by the RAD to cool to 180 degrees your stablized temperature will rise until the RAD can maintain that temp.

 

That said, it sounds like you might have some rad, water pump or coolant flow problems (including trapped air). OR a bad temperature sender or gauge.

[rotoruter2001]

the thermo will just allow coolant to flow at 180 degrees not 200 degrees. the real key for bringing it down more would probably be the fans. a power programmer or something can be bought to reset the fan temps for the lower temp thermo. it wont hurt having that thermo in, but i wouldnt expect any differences really in tep. i had a 210 thermo i replaced with a 160 in my TA and no real difference.

[1999GMCZ-71]

reg fan on the trucks. Wish it was electric.

[toddgotfish]

i've been told the temp guage in the cab will not fluctuate

unless an extreme condition occurs (high overheat)

but i am definitely interested in your MPG gain / loss

please keep us informed

i want to do the same thing to my 00 sierra

but need input first

Thanks

[1999GMCZ-71]

i've been told the temp guage in the cab will not fluctuate

unless an extreme condition occurs (high overheat)

but i am definitely interested in your MPG gain / loss

please keep us informed

i want to do the same thing to my 00 sierra

but need input first

Thanks   

I'll do that. My mpg before the thermostat change was about 16 mpg. That is city and highway, and a few wide open passing and such hehe.

[cyrylyn]

you're not likely to increase your MPG by putting in a lower stat. The key to not blowing up your engine is to get rid of the heat, not lower the temperature. the coolant flowing back into the engine from the radiator might only be a degree cooler, but it's lost BTU's of heat.

[raventai]

suposedly we have an “idiot” gage GM did not want to bother the driver with fluctuation's in temperature so it just shows cold warm normal and overheating

 

 

if you watch it during warm up it does not slowly move up it has spots it moves to and then just stops on normal just below the center of the gage