Just started my long commute again after a summer off. The last thing I did this summer was to flush my coolant system really well. What prompted this was me finding out my heater did not work. I actually thought I flushed things out "good enough" when I did my head gaskets but I guess not.

My heater was completely clogged and I had to use pressurized water to get it unclogged my radiator and engine was pretty filthy too. I ran pressurized water (garden hose) through the radiator, heater and engine until clean and then cycled through running the truck with water, draining, and hosing it out 4 or 5 times until the water was coming out clear and with no chunks. Refilled with premixed green coolant of some sort from Walmart (prestone probably can't remember off the top of my head). I also added a little bottle of UV dye in the event of my front cover leak returning.

Anyhow onto the results... Before the flush I was idling at 105 Celcius (220 F) and running at around 98 C (209 F). After the flush the engine idles at 99 C (210 F) and runs at around 93 C (199 F). I have not seen my coolant break 101 degrees C since the flush. I have not a clue if those numbers above are good or bad relatively speaking but I'm thinking that dropping my engine's operating temp 10 degrees F on average is a good thing. My viscous fan rarely comes on either anymore. All the other live data feeds from my scanner seem to be fine so it does not look like I am running too cool plus the engine is running better now than ever.

So all you who have been neglecting your coolant maintenance go clean things out it easy and cheap and you won't be able to do it once winter gets here. A couple opinions that I have formed after this is that water wetter does not do a thing when used as a coolant additive and that the temp gauge on these trucks are not something I would want to rely upon to tell me my truck is about to overheat. By the time the needle would start to move the coolant would already be too hella' hot. I'm adding a scan gauge 2 to my xmas list this year.

 

Using my OBDII scanner's live data my trucks runs at 196*F on the expressway and 200*F when sitting in traffic.
When it is 95*F and off roading for 2 hours it will climb to 210-215*F but she has only once got hotter than 215*F and that was before I discovered that my clutch fan was not working.

Water Wetter is a gimic, if you need a additive then you need a new fluid/oil.

Did your truck have DexCool?
http://sancarlosradiator.com/dex-cool.htm

 

No I switched from Dexcool a couple years ago. Not soon enough to save my head gaskets.

 

How many miles did you put on your rig using dexcool lip?

 

How long have you had the truck? The reason I am asking is, I don't see Dexcool as being that bad that it plugged up everything, could someone, including your self, put some form of stop leak in the system to do a cheap leak fix?

 

Bought the truck at 55,000 miles. Changed the dexcool out at around 75,000. The mechanic supposedly did a flush at the time (this was pre DIY). Then at about 95,000 head gaskets started to leak and the truck eventually lost coolant and overheated. I did the head gaskets at around 100,000, did a drain and ran water for a few minutes as a flush. I don't think the deposits were from the dexcool per-se but from a combination of the overheating and age.

I am pretty impressed at my running temps now. Before I could feel and smell (coolant evaporation from overflow) the heat from my truck after a long commute. Now it is all relatively cool. I even double checked my thermostat was closing because I was worried. But after a couple weeks driving around with a scanner hooked up everything is as it should be.

 

Dex-cool + Green/normal Coolant = a plastic/sludge substance.

There was probably some left over dex-cool somewhere that mixed with the green coolant.