DexCool and Plugged Heater Core - What I did to remedy

[99XC600]

That's a great fix. How much time did it take to do all of this? I agree with you putting the Dex back in. I use it...even on a newly rebuilt motor.

One thing you mentioned about water not being a very good coolant? The only reason we don't use pure water is due to corrosion and freezing. Water is a much better coolant than water/glycol mixture.

I think I started around 12:00 PM today and I finished up around 2:30. That included going to the parts store when I realized the thermostat gasket was leaking and had to be replaced.

Interesting on the water being better overall. I always thought that the antifreeze (Dexcool or Glycol Based) had better heat transfer abilities and a higher boiling point. I'm sure I could be wrong though.

[Rico]

I think I started around 12:00 PM today and I finished up around 2:30. That included going to the parts store when I realized the thermostat gasket was leaking and had to be replaced.

Interesting on the water being better overall. I always thought that the antifreeze (Dexcool or Glycol Based) had better heat transfer abilities and a higher boiling point. I'm sure I could be wrong though.

Never said it was better overall.

The mixture is an azeotrope so you are correct, boiling point would be higher. Although, with the system under pressure the BP of pure water would be raised quite significantly.

Pure water is still a much better cooling agent than the ethylene glycol/water mixture though. Running an engine on pure water temporarily will have no harmful affect on the engine relative to temperature. It would actually run a little cooler.

At work we run pure deionized water through everything; copper, stainless steel, steel, aluminum, plastic etc. When the parts are serviced, they look brand new. Can you believe it? The difference is that our system has resin beds that constantly remove ions from the water. It's not the water that causes corrosion it's the ions that are dissolved in the water. The required heat transfer from equipment to coolant is very high so a glycol/water mixture would be detrimental. Also, the equipment never sees freezing temperatures making pure deionized water the perfect coolant.