Temperature gauges are notoriously inaccurate. Most thermostats open at the correct temperature, but some do not. About a year ago I replaced an old thermostat that opened at about 185 degF with a new one that opened at about 205 degF. Both were rated for 195 degF. The rated temperature is the temperature at which the thermostat is supposed to start opening. If you put a 195 degF thermostat in a pan of water and heat it, it should start to open at 195 deg and be fully opened at about 210 deg. When my new thermostat was only half open with the water boiling I new it was out of specs.

Libby Chantel wrote:
>
> My 96 chevy truck was running cool according to the temp gauge so when
> I replaced the water pump, I flushed out the cooling system and put in
> a new 195 degree thermostat along with Dex-Cool antifreeze. Now it runs
> even cooler! It is my understanding that the engine runs more
> effeciently at the design temp, 195. If this is true, how in the heck
> do I get it to run hotter? It used to run hotter when new... Maybe the
> gauge is lying to me? Maybe the thermostat (a Thompson from NAPA) is no
> good?
>
> Would you guys please advise me on what to do?
>
> thanks,
> Libby

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Mike Walsh
West Palm Beach, Florida, U.S.A.