ksbowhunter44

Guys, Need some help diagnosing an issue with my 2014 Silverado Double Cab LT Z71 5.3L…. Last week I was towing my boat (boat and trailer weigh under 2K) home on about a 2 hour drive and I noticed that my truck was running a little hot. I was cruising around 75mph and it would intermittently heat up to the next hash mark above 210 degrees and go back down to 210, but stayed in between the two marks on the thermometer most of the trip. Also, my transmission was running about 212-215 degrees and I have installed the new ~156 thermostat on my transmission so I thought it was odd. I have 120,000 miles on my truck and no known leaks so my first thought was that the coolant had degraded since I had never changed it. I drained the radiator, and the coolant that came out looked like it was brand new. It was not off colored at all. I proceeded with a good flush of the system with distilled water, then added new Dex Cool. The truck was still doing it any time I step on the gas or drive highway speeds. I live on dirt roads, so my next thought was that my radiator might be dirty enough to not let air pass through, so I blew it out with low pressure and rinsed it out with the hose while it was cool. No change, the truck was still overheating slightly at higher RPM’s I was due for an oil change, so I changed my oil at this point to make sure it didn’t have any water in it. Oil was clean and had no water. Still no change. I replaced my thermostat about 6 months ago because the factory one was stuck open and I had no heat. I used whatever they had available at O’Reilly at the time. I replaced it yesterday with an AC Delco thermostat and housing to see if that had any effect. The truck is still doing the same thing. Any advice on what to look at next? I have a trip coming up in 2 weeks, and I am trying to resolve this before towing my boat on a 2 hour trip. A water pump and radiator will run about $800-1000 and I don’t want to waste anymore money on parts I don’t need. The coolant appears to be circulating fine I was able to watch the overflow tank go from clear to orange after adding dexcool after the flush. Will try to post a video of the temp gauge after I drive it tonight. Thanks in advance.

I did install the lift kit myself. Not too difficult, but a little tough torquing all of the bolts without a car lift. I am getting about 14mpg that is about 60% on highway at 80mph and 40% around town. My speedo is only off 1mph at 80mph (speedo says 80 when actually travelling 81) with the 285/65. I tow a medium sized tractor a few times a year, but have not done so since the lift. The tires I am running are only about 1" bigger than stock (32.6" diameter) so the power difference is negligible.

Thanks! They were in the first post. Darn thing said my files were too big to post both pictures at once. 2014 Silverado Z71 Blue Topaz Metallic 4" BDS Suspension Lift 18x9" Fuel Boost -12 Offset w/ Fox Shocks and Coilovers Fallen Wildpeak AT3W 285/65 r18 Going to bump up to some 305/65r18 tires next time.

Here is my 2014 2014 Silverado Z71 Blue Topaz Metallic 4" BDS Suspension Lift 18x9" Fuel Boost -12 Offset Fallen Wildpeak AT3W 285/65 r18