Overheating issue-Not engine

[beav626]

My Escalade 2003 EXT with the 6.0 is having a odd overheating issue.

When it is Summer in Oklahoma or above 90 outside my truck will be cruising along fine but when I stop or cruise in town My External Temp gauge (on mirror) starts to climb rather fast. Then my AC starts to kick on and off. This is mainly while Im sitting still
My mirror has read temps as high as 145 degrees....

My engine temp is normal and my tranny temp is just under 200

Any thoughts here?

 

[chevyboy831]

sounds like the temperature sensor for the exterior temp is toast... unfortunately... i dont know where it is... ive never fixed one...

 

[beav626]

That's what I thought too- but it reads correctly while cruisIng around

 

[DeepSeaFish]

If I remember correctly, the external temp sensor is located on the radiator housing. But that sounds like your problem with the huge temp fluctuation.

 

[beav626]

well it got a tad warm here in OKC today... 103 with a heat index of 1,000 degrees.

driving around town all was good. External temp was close to normal, coolant temp stayed at normal, tranny temp was normal to warm, around 200 degrees.
This evening a towed my boat to storage and while it was an easy tow for the 6.0 once I got to the storage place I let the truck sit for a bit (running)

When I got back in the truck the External temp was 134, the coolant temp was between the 210 and the next tick up. Tranny temp was good.

The fan is spinning normally, and I cleaned the radiator grills

Also once I drove off all the temps came back to normal