It's gotten pretty hot again here recently; 100°F at 06:00 hrs, and usually in the 118°F-125°F range by the time I get off work around 16:30 hrs.
The 4.2L L6 in the Envoy has a 195°F thermostat, which is alright during the cooler months of the year, but does make for some cringe worthy moments in the summer as my eyes are glued to my ScanGuage-II. A reading of 216°F at a constant 62 MPH, and anywhere between 218°F-224°F waiting at the lights is common, sometimes hitting the 228°F-234°F mark in heavy traffic. If I turn the air conditioning off, coolant temperatures will slowly drop, but the truck also becomes a moving oven, so it can be a bit of a delicate balance. The 50 MPH mark seems to be this vehicle's sweet spot with the AC running, where coolant temperatures will be in the 200°F-206°F range when cruise control is engaged. But that's not exactly a safe speed to be driving at on any highway here either.
If memory serves me right, a 50/50 mixture of Dex-Cool and distilled water has a boiling point of 265°F, which is exactly what I have in there. The electro-viscous fan on this application has been tested and functions as intended; attached are the factory stock settings for those interested, when the electro-viscous fan will fully engage.
While a tune to lower temperatures and pressure points in the stock settings is a possibility, along with changing the coolant concentration to something like 70/30, and perhaps a higher pressure radiator cap along with a lower temperature thermostat, I'm more interested in the long term affects of these coolant temperatures, such as the impact on the lifespan of gaskets, seals, etc.
With the exception of cooling system components - specifically radiator hoses, water pump, thermostat, radiator and radiator cap - all seals and gaskets are factory original and do not leak. The replacement cooling system parts are GM Original Equipment, not ACDelco Professional or Advantage, or aftermarket. The vehicle has accumulated approximately 146,000 miles over the years and has zero issues, and no oil consumption between intervals.
After driving in the summer, I will pop the hood and allow the engine to idle with the air conditioning off for at least 5-8 minutes, until coolant temperatures drop of a minimum of 198°F before shutting off the engine. While this is a "feel good" thing for me to do, how much of an overall impact does this really have?
The 4.2L L6 in the Envoy has a 195°F thermostat, which is alright during the cooler months of the year, but does make for some cringe worthy moments in the summer as my eyes are glued to my ScanGuage-II. A reading of 216°F at a constant 62 MPH, and anywhere between 218°F-224°F waiting at the lights is common, sometimes hitting the 228°F-234°F mark in heavy traffic. If I turn the air conditioning off, coolant temperatures will slowly drop, but the truck also becomes a moving oven, so it can be a bit of a delicate balance. The 50 MPH mark seems to be this vehicle's sweet spot with the AC running, where coolant temperatures will be in the 200°F-206°F range when cruise control is engaged. But that's not exactly a safe speed to be driving at on any highway here either.
If memory serves me right, a 50/50 mixture of Dex-Cool and distilled water has a boiling point of 265°F, which is exactly what I have in there. The electro-viscous fan on this application has been tested and functions as intended; attached are the factory stock settings for those interested, when the electro-viscous fan will fully engage.
While a tune to lower temperatures and pressure points in the stock settings is a possibility, along with changing the coolant concentration to something like 70/30, and perhaps a higher pressure radiator cap along with a lower temperature thermostat, I'm more interested in the long term affects of these coolant temperatures, such as the impact on the lifespan of gaskets, seals, etc.
With the exception of cooling system components - specifically radiator hoses, water pump, thermostat, radiator and radiator cap - all seals and gaskets are factory original and do not leak. The replacement cooling system parts are GM Original Equipment, not ACDelco Professional or Advantage, or aftermarket. The vehicle has accumulated approximately 146,000 miles over the years and has zero issues, and no oil consumption between intervals.
After driving in the summer, I will pop the hood and allow the engine to idle with the air conditioning off for at least 5-8 minutes, until coolant temperatures drop of a minimum of 198°F before shutting off the engine. While this is a "feel good" thing for me to do, how much of an overall impact does this really have?