What is the "Normal" operating temperature?

[1974StepSide]

I installed an autometer temp. gauge today. My factory gauge hasn't worked since I've had the truck.
I also replaced the Thermostat with a 195 degree unit.

When I went for a test drive to check if the gauge was working, it went up to about 210 at it's highest and stayed a little lower after that.

At what point is boil-over? At what temp should I be concerned that things are getting too hot?

What temp. do you run at on "normal" days?

[Russell]

Mine has four ticks, dunno what the temps are, but it usually sits 3/4 of the way to the first tick.

[1972C10]

water boils at 230 i think but water and antifreeze boils at like 260 maybe? i could be wrong thou. Ive got a factory gauge that registers 210 with a 195 degree thermostat .

[silverado_ss03]

i wouldn't know, my factory guage doesn't work.

[allthrtl]

The temp that water boils at sea level is 212º F. Now, in an automotive situation, the more pressure the water is under, the higher the boiling point, don't have the specifics here in front of me, but you get the picture. Also, the coolant you add to the system also raises the boiling point.......

Anyway, I run a 180º thermostat and my guage stays about 187-190º most of the time. A really hot day in traffic it will easily get to the 200+º mark, but I need a bigger radiator.... So, I guess 205-210º is about right for that thermostat...I don't know what the climate is where you live but, I never go above a 180º thermostat in my arrid climate.....


HTH
Michael

[crackajacka]

i run a 170 thermostat and i run 180 -190 regaurdless unless im really pushing it like 80-90 on my th350trans. when i shut my truck off the temp rises to 200-210 depends on how hot it is outside

[toytruck]

mine shows 210 allday long.

[Tom]

My facotry gauge stays at the 1/4 way mark which I've decided is about 175*. With the 160* thermo in it would be right below it at normal temp. In 110* AZ days at 80mph for an hour it will get to the half way mark [about 210* or so] I put a 180* thermo in for the winter and it sits just above the 1/4 mark now at normal temp. And this is with a 3 core radiator and high flow water pump.

[PHOENIX]

I also have autometer gauges (and love them )
I have a stock 350 with 4-core rad and 195 thermostat.
I also run a dodge/jeep factory electric fan for v-8 engines.
Most the time the fan isnt on.
Even when the fan is on it acts the same as far as temp changes and low/max readings).
First thermostat cycle of the day it gets up to around 210 degrees then lowers down to 170 or so. After the first cycle its anywhere between 180 and 195. You can actually watch the needle go from 180 up to 195. Right when the needle hits 195 it drops right down to 180 and starts over again.
If I shut the truck off and come back out in a minute or two then it gets up to 220 degrees.
The gauge is accurate and shows all temp changes, you really cant ask for more.

I replaced my thermostat this weekend along with a few other things and noticed the reading got up to 230 or so before the thermostat opened up for the first time. After that "break in" it was acting the same as before. I suggest you keep the 195 thermostat.

[bigblock73]

Mine never went above 200...usually stayed between 185-190 all day long.

That was with a 3 row radiator, 190 thermo (I think), and a clutch fan.

[1974StepSide]

Thanks for all the input guys, I knew I could count on getting the info I was looking for!

[old Rusty C10]

water boils at 212 degrees when you put the pressure cap on it you allow the water to get hotter before it actually boils my trucks run at about the first mark on the guage and i havent a clue what temp that is when i change the thermostat ill check the book and see whats recommended and use that prolly 195 degree.

[86SILVERADO]

205 to 210 for me with a 180 thermostat and a 350 with a three row.

[apstguy]

My 305 has never gone above 200. That is with the stock gauge - not all that accurate but it works. It has creeped to 210 after the choke got stuck on on the freeway. It dieseled when I shut it off at that temp.

[thrtsxchambers]

Bringing up an old thread but I need more info on this. I have a 388 in my 83 c10. 3 core radiator, 165 thermostat and dual electric fans. At idle it hits around the 210 mark on the stock gauge. I shut it off before letting it get any higher and let the fans run for a minute after shutting it off. Any input if that temp is ok for that motor? I do not have the overflow tank installed yet, not sure if that would make a difference. I haven't driven it yet to see what it reads while driving.

[74CustomK20]

Originally Posted by thrtsxchambers

Bringing up an old thread but I need more info on this. I have a 388 in my 83 c10. 3 core radiator, 165 thermostat and dual electric fans. At idle it hits around the 210 mark on the stock gauge. I shut it off before letting it get any higher and let the fans run for a minute after shutting it off. Any input if that temp is ok for that motor? I do not have the overflow tank installed yet, not sure if that would make a difference. I haven't driven it yet to see what it reads while driving.

Pull the stat and sticker in a pot of water with a thermometer. See if it's working right. If it is (assuming cooling system parts are new) I'd look at your rad being too small or something is plugged somewhere.

[TrailerTrash]

Verify the actual temperature with an infrared thermometer

[Dead Parrot]

I wouldn't worry too much based on temps reported by a 36 year old gauge. Quite possible the sender in the motor isn't matched to the gauge in the dash. Several threads on that issue.

2nd the suggestion on an infrared thermometer.

Could also buy a new aftermarket gauge and install the sender in the opposite head or in the intake. You could just leave the 2nd gauge in the engine compartment or laying on the cab floor until you are satisfied that the dash gauge is reading correctly.

Keep in mind that the stable running temp for a t-stat is 10~20 higher then the listed temp. The listed temp is when it starts to open.

[DieselSJ]

For those of you who want to know the relationship between pressure and boiling point -

[blindbug]

I just spent labor day weekend dealing with replacing a busted water pump. 350 with a stock (or at least a direct replacement) radiator, 50/50 coolant. We flushed the rusty coolant with the waterhose from both the radiator and the heater core. Replaced the upper, lower, and heater core hoses, replaced the 190 themostat with a 180 and replaced the water pump with a carquest brand. Drove the truck 3 hours in 90 degree weather and never cracked 190 the whole way, going 60+ (with a high speed of 79). Might have got near or slightly over 190 when I hit a half hour traffic jam due to a wreck. This, on a 1976 350, which MAY have been rebuilt at one point in its life (but not during my ownership). Sending unit is a Dakota Digital with DD gauge set, so should be fairly accurate.

Just some food for thought on the running temps in these old trucks.

[SCOTI]

Airflow through the radiator impacts temps.
Water pump condition impacts temps.
Thermostat range impacts temps.
Coolant passage conditions impact temps.
Gauge location impacts displayed temps.

Several variables to consider.....

[thrtsxchambers]

Everything is brand new, even the temp gauge since I broke the stock one 2 days ago. I haven't been able to check it again. I hope to drive it this weekend and see how it goes.