Unless it 130' outside . Lol

 

Oops, sorry. I meant those are temps while running. Drove to Philly and it was in the 30's out, and the warmest my engine got was 140's

 

I noticed the same thing last week. Drove from Georgia to Kentucky, intake air temp stayed around 40-50 deg and the engine was mostly in the 150's-160's. (In the summer it got up in the 220's quite easily, much to my alarm.) So, yeah, the ambient temperature under the hood has a lot to do with the running temperature of the engine. I might just put vents in the hood to keep it under control.

 

If you guys are running that cold your t-stat is bad, its stuck open and needs to be replaced.
Believe it or not a stuck open t-stat can cause hot run conditions because the coolant is not staying in the radiator long enough to be cooled.
I use a 195 t-stat and my truck runs right 195-200 winter and summer.

 

Ok, that was my worry. Thanks spike.

 

Which stat are you using Spike? (I have the Auto Zone 180 "failsafe.")

 

Your fail safe thermostat has gotten to the hot temp once, and ratcheted to the stuck open position. A D1 (like mine) will run at 140-150F in 90F weather - if no thermostat installed (or latched open). Change stat to conventional 180F, with the little jiggle device in the flange, that goes at the 12:00 position.

 

I bought it at AutoZone many years ago, its a 195*F, not the failsafe one because every single t-stat that I have ever ran into that has failed has failed in the open position.
In my opinion the failsafe one is a gimmick to get more money out of you for the exact same thing.
I do not know what brand it is.

 

Good advice, thank you gentlemen. Lesson learned.
And... here we go. Copper or brass? I'm thinking brass would be less prone to corrosion... but it might be a moot point if the coolant gets flushed and the thermostat changed regularly. Any opinions/thoughts on the subject?

 

Goes in this hole, spring inside block. You knew that but noob # 23578 may not. Same stat fits like 3000 plus vehicles. IMHO if you drive in Atlanta traffic the 180F is a good choice. It will be made out of stainless and brass, like one on right. If it does not have a jiggle device in the rim you can drill a small hole. That goes at 12:00 position. The jiggle device or vent hole at 12:00 allows steam to pass by, and not form a pocket. If a pocket forms, the stat may stay closed too long and engine overheats. If you want to test just pop in a pan of water on the stove (with approval from SWMBO - I am only approved to wash pots, not operate them).

With the 180F stat my D1 pokes along at 178 - 183 on the secondary roads, and maybe up to 187 on the highway. Once in a while will bump into the 190s. Is that a safe temp? Has been for my KIA van, 180F just about always and 243K. In the old days the spec stat for the Buick Skylark was 180F. The 94 Defender manual in the RAVE shows a pix of a factory stat stamped for 82C, which would be 179F. The higher temps are used to comply with the clean air requirements, not make engines last longer.

Yes, trucks in the frozen north will enjoy the 195 stat. And if your cooling system is in tip top shape you can deal with it in summer. And I can recall when we changed stats by season (winter / summer).