M37 Thermostat?

[Rich Johnson]

What temp should I use?

Im in San Diego, but it does get hot out here especially when cruising the mountains and desert, grades combined with 100deg outdoor temps is common in summer.

My truck has been sitting for about 6 years, 3 or 4 with the coolant system open and getting crusty....

I think it was a 160 I had in it but that seems too low, once the engine warms up the T stat will open and stay open and not cycle closed, allowing the coolant to cool down in the radiator RIGHT?

I put in a 180 and my buddy swears I screwed the pooch on this, that I have to use a 160 to keep the engine cooler.

Can somebody set me straight?

 

[Bill W]

That debate can go on forever, I've had alway run a 160° but the best reason I've heard ( but don't nessassarly agree with ) about running a 180° is that at that temp you'll burn off more acids and such that build up in the oil from lack of use. I believe that running a 160° under the hood means cooler running and less chance of vapor lock...

 

[Storm 51]

My understanding is that the engine is happiest at 180 degrees. If you are operating in conditions where that temperature is likely to be consistently exceeded, then you need a cooler thermostat.

Driving in California, especially in the deserts and on mountain grades, a cooler thermostat would probably be the better choice.

In short, it all depends on the conditions in your AO and the way you operate your truck.

Storm 51

 

[rosco]

If your cooling system is clean & functioning properly, the truck will run adequately & stay cool, regardless of the temperature of the thermostat setting. Even when your running a 205* thermostat!

 

[EMD567]

The cooling system is so large in comparison to the engine, the thermostat will cycle, even with a 180º. Get a laser temp gun, and check the temp at the top and bottom. You should see at least a 30º change in temp.

 

[Squirt-Truck]

You will like the 180 better, it helps with the accelerator stumble. If the cooling system is good, no issues.

 

[BrutusM37]

I run a 180 in SE Virginia with no issues. I had some vapor locking problems this past summer but that was due to the previous owner mounting an inline fuel filter in between the pump and carb (?) and the fuel lines were rubbing on a coolant line. Relocated the filter to the frame rail under the bed and made a new hard line between pump/carb that hooked away from anything hot. No problems since.

 

[GUNNY 155]

I am running a 180 degree thermostat. I am in the Chicago area and we have hot summers with some days in the high 90's If all parts of your cooling system are up to spec you should have no problems even on a summer day doing a parade.