160 thermo. Heat spike at 107° weather.

[ROGELIO A GUZMAN]

So this weekend I went to las Vegas. I had 0 overheating issues in California weather. My Yukon stay well under 200 degree all the time here in Los Angeles weather. So I decided to drive to Hoover dam and it was 107. I did notice my temp go up to 203. Is it because the 160 thermo is not closing and keeps the coolant circulating? I did buy the OEM 187° thermostat last month but haven't installed it. If I swap for the 187 it should keep the coolant longer in the radiator right?

 

[Doubeleive]

possibly, what made you decide to install a 160?
how old is you radiator?
typically heat issue's like that are because the radiator is not cooling properly and needs to be replaced
if the radiator was replaced did you use oem or some aftermarket? there is a restrictor valve on the oem radiators on the small line leading to the reservoir tank if there is not enough restriction then cooling does not work properly and coolant constantly flows bypassing the thermostat, some of the aftermarket radiators do not have the proper restriction.

 

[afpj]

203 is a heat issue? I idle at about 205 degrees in the high desert summer when the engine is fully warmed up. Freeway cruising it goes to about 197.

02 yuk, 4x4, 5.3 FF, stock. 206k miles. Original rad.

 

[bigdog9191999]

electric fans dont usually turn on till about 210-220. so think about that. and honestly going below about a 180 your not gaining anything and could actually be hurting mileage and such, esp if the pcm isnt tuned for it.


the thermo opens at the temp selected to allow the radiator to keep everything cooled off. once it opens thats as much cooling as you can get. so if your getting too hot then there is an issue with part of the cooling system. pump, rad, fans ect.

 

[ROGELIO A GUZMAN]

possibly, what made you decide to install a 160?
how old is you radiator?
typically heat issue's like that are because the radiator is not cooling properly and needs to be replaced
if the radiator was replaced did you use oem or some aftermarket? there is a restrictor valve on the oem radiators on the small line leading to the reservoir tank if there is not enough restriction then cooling does not work properly and coolant constantly flows bypassing the thermostat, some of the aftermarket radiators do not have the proper restriction.

I replaced not so long ago pump, fan clutch ,and OEM radiator. I did the 160 thermo thinking it would keep the coolant colder. It does when it's cool outside. But the 107° weather did make the coolant get a bit high. Well higher than normal.

 

[ROGELIO A GUZMAN]

203 is a heat issue? I idle at about 205 degrees in the high desert summer when the engine is fully warmed up. Freeway cruising it goes to about 197.

02 yuk, 4x4, 5.3 FF, stock. 206k miles. Original rad.

Oh ok. So 200° is kinda normal? I'm used to lower temps on my other cars. Lol

 

[ROGELIO A GUZMAN]

electric fans dont usually turn on till about 210-220. so think about that. and honestly going below about a 180 your not gaining anything and could actually be hurting mileage and such, esp if the pcm isnt tuned for it.


the thermo opens at the temp selected to allow the radiator to keep everything cooled off. once it opens thats as much cooling as you can get. so if your getting too hot then there is an issue with part of the cooling system. pump, rad, fans ect.

I'm new to the Yukon world , so I think I'm not used to seeing 200° temps on engines. From the other replies, 200° is kinda normal. I have a new pump, fan clutch ,OEM radiator. I think I'm going back to 187° OEM thermo. So that way the coolant stays skittle longer in the radiator and cools off some more. I also put a HD fan clutch so it pulls more air.

 

[ROGELIO A GUZMAN]

At what temperature should I consider a over heating issue. Sorry for the dumb question but you guys have had Yukons longer that me.

 

[ks03]

I wouldn’t call 220 overheating, but I don’t like to see it sustained there. 225 and I’d be concerned, and 230 I’d say something needs to change even in extreme conditions

203 doesn’t seem unusual for the conditions. In a perfect world a fan clutch would freewheel until it was needed like an electric fan. Gm put an electronic fan clutch on trailblazers and envoys to do that, which theoretically is probably the most efficient way to do it, but they had issues too

 

[Scottydoggs]

200 is actually cooler then normal. gm cars and trucks all run 210. id still put the stock temp t stat back in tho. the 160 is just stuck wide open. the 190 will at least cycle like normal.