I just want to share the progress of an issue I'm having hoping to help another form dweller with the same problem in the near future.

My 2004 blazer XTR (107k) was overheating within a 1-2 mile drive. It started out where it would last a week then a day, then it eventually made it down to a useless 1-2 miles.

I noticed the radiator and lower radiator hose felt cold even when the temperature gauge was pegged out at 260. Also, fluid was spew out the radiator and the resivor was bubbling. But no leaks anywhere except the overflow valve when it was hot.

I simpily replaced the thermostat (under 10 dollars) and it SEEMS to be back to normal. I think change in the weather pattern down here in sunny Soutwest florida (lows of 45 degrees, BRRR!) put some stress on the cooling system.

If the problem continues later I'll add to this post. Hope this helps.

 

Yup, thermostat or an air bubble. Air bubbles can be frusterating because they don't always "pop" up at the same temp/time. Could possibly be the water pump too for that matter, but that would be more consistant.
The lower rad hose (return line) & the rad being cool tells you there isn't the circulation that's supposed to be there.
WTG at reasoning things out & deciphering what's wrong.
BTW I don't believe it's the change of climate, more that the stat is old.
Have you checked the coolant for proper ratio & not gunked up/contaminated with debris?