So I drive a 68 f100, 360 auto 2wd. Was wondering what temp thermostat everyone is using. I haven't owned the truck long but it seems to never get but up to the cold level. With the weather being really cold right now in Ga and our summers boiling is this Ok? Or should I change it to get it warming up? Mainly cause I'm freezing in the cab...

 

You can get a 180* and see if that works well enough now. The 195* is what is suppose to be in there but if you don't have enough radiator cooling it might get too hot in the summer.

As for freezing, these trucks don't have much for any insulation so they get COLD if you drive on the highway much. I know I use to freeze when I drove my '70 every day back in the 90's. Heater worked well, but the cold draft was too much.

 

I run a 160 as the summer heat in Texas is like trying to get acclimated to the sun.
I run an Arkansas thermostat in the colder months. ( a piece of card board that covers the better half of the radiator.

 

When, I was living in Carson city Nv. for a few yrs winters were down to 10*+ zero snow sometimes, I ran with about 1/3 covered of the large camper special rad with 180* thermostat was enough to warn your feet some what.

Orich

 

Well at this point in not sure there even one in the truck. Just drove it to the parts store, about a 30 minute round trip and the gauge never changed. Either faulty gauge, no t stat, or stuck open t stat. But, it does move when ignition turned on, I guess I'll go ahead and buy a new one and install it. Better safe than sorry

 

To test the gauge & sending unit remove sending units wire an ground to motor make sure it's grounded good then go switch on the ign key if it's working the needle will swing to hot. Don't leave the key on very long like that.

Orich

 

195° in the winter. Trust Me. 180° in the summer, maybe. If you feel you must, for some reason.

Found 180° not sufficient for winter use, it's a "tease" even full blast, the difference in heater output is major. With a 195° it "will run you out", normally the blower can be left off for a comfortable setting. The whole notion of running an engine cool as possible is not correct in the first place. Maybe Death Valley is different, or Arizona.

Summertime use, if radiator and block are clear it won't have any trouble at all with it, I am too lazy to swap t-stat around twice a year so leave 195° year round. That is basically what an engine is designed for, it will run better and have far less cylinder wear and oil contamination and sludge buildup.

 

180° but I'm in the SF Bay Area of California... also known as "Dum****istan" due to the majority political orientation of the populace.

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Use the 180* version and then some cardboard in the front of the radiator for any really cold snaps?

 

Sounds to me like somebody did a thermostat delete. Use a infrared point and shoot thermometer to determine if the if its warm or not. Could be the heater core is plugged up. I had a bad experience with the ole cardboard in front of the radiator. Didn't know the previous owner had it there which caused me to overheat.

 

What does the manual spec?

I'm aways surprised when folks think they have a better idea than the engineers who built the truck. It's all designed to work best and most efficiently as a system together. This is especially true with computer engine controls in modern engines but it's no less true going back a hundred years.

Even my old slick the manual sez "All Engines"
thermostat:
opens at 185° - 192° F.
fully open at 210° - 212°

Keep in mind a thermostat controls the *minimum* temperature, not the upper temperature.

It's up to the radiator, fan, cooling jackets etc, to keep the upper temperature within limits. Also keep in mind there's a lot of junk parts out there today, thermostats that never met or won't hold spec. If the radiator or engine is full of rust, sediment, and scale, a lower rated thermostat won't help you.

Basically the idea for any engine is for it to reach normal operating temperature - that's north of 200° - as quickly as possible, even if you live at the Equator. This minimizes sludge buildup, and cuts cylinder bore wear by half, lowers pollution, and improves mileage. If you've torn an engine down that ran without a thermostat for any length of time you'll understand. Sludge city! Oil temperature lags coolant temperature by quite a bit. When the engine runs cool it is unable to burn off the acids and combustion byproducts (water) in the oil.

 

I actually used to get my hands on 205 stats when I lived in Alaska, ran one year round in my 72 and it kept the truck pretty comfy in 20-30 below.
I always say run as hot of one as you can. As long as all the coolant stays in the system, it isn't too hot.

 

Has a brand new heater core installed this week. I'll have to test the sending unit.

 

just checked it. Initially went to hot. What does this tell me? Obviously the gauge works.

 

All finished... parts store trip and got an own temp of 195 thermostat. Went home took the housing off and..... no stat.... installed the new one and everything is a ok.