08 Denali engine overheating

[rubicon1976]

My 08 Yukon Denali 6.2L just started doing the same thing last weekend. I was pulling my ~5000lb trailer into the mountains and it overheated to the point where it shut off on me. An hour or so later it started up and seemed to be cooling fine but I noticed pulling up even slight grades for extended periods between CO springs and Denver the temp would start climbing pretty quickly. I've been driving it around Denver all week with no trailer and it has been fine. Did you ever find the problem?

 

[Doubeleive]

swap out your radiator, my opinion is most will get clogged up after 5 years, you can try flushing it and running some chemicals thru it but it might not do much good if you haven't already been doing that annually.
1800radiator has a 1 3/8" radiator with both trans cooling and oil cooling lines (if you are so equipped) if not it doesn't matter it will still work
they have also added a drain **** that GM so thoughtfully deleted
and it has a lifetime warranty
choose #103285 it will fit all 07-13 Tahoe, suburban, Yukon, Yukon xl, escalade, escalade esv. and probably many other full size trucks

 

[gpracer1]

General rule of thumb assuming the thermostat is good and fluid level is full......
Poor cooling at low speed or low load is usually air flow problem.
Poor cooling at highway speeds and under heavier load is usually water flow problem like clogged radiator.

 

[gooffeyguy]

What is the trans temp both when and when not towing?

Sent from my SM-G930V using Tapatalk

 

[muncie21]

Another vote for looking at the transmission side of the issue