03 1500HD overheating only while towing

[EvilWS602]

We did a very minor tune when we turned the fans on over two and half years ago. We really just adjusted a few things to try and help the mpg in that pig. I'll get my him and have him check the timing and the tune just to see. I was going to have him re-tuned it for some more ass after a few performance mods to get a little more grunt out of that turd, but I've grown tired of spending time and on money on that truck.

 

But to answer the question. Truck ran fine for 2 - 3 years after being tuned.

[Levahj]

I know this was almost exactly 5 years ago, but I want to ask you Clint if you ever found out the cause of your overheating when towing?   

 

My situation is the same but with a 5.3 liter 2003 suburban.    Had a 2002 suburban for 16 years and towing ~5000lbs the thing barely ever got hot at all.   Hardly remember the gauge going past ~1 o'clock ish on the worst grades in the Sierra's going up to Tahoe. 

 

Now I have the 2003 with an E-Fan, towing Cam, and cold air intake mods along with a tune from BlackBearPerformance and the damn thing is almost hitting the red when going up the same grades in the Sierra's.

 

Any ideas on why the heck this is happening?