The Dexcool question is based on two issues: sludge and intake manifold gaskets. Sludge is associated with (but not proven to be caused by) poor maintenance of the cooling system. The first source has a good rundown on the whole controversy. If you have not had sludge problems, keep up the maintenance and it is unlikley you will have sludge problems.
The intake manifold gasket issue depends on engine and year. GM has demanded Dexcool be used in all their engines since 1996. But it turns out that the intake manifold gasket materials were not compatible with the 2-EHA used in Dexcool, and in the V6 and V8 engines the coolant ran through those gaskets. See the second source. A lot of GM V6 and V8 engines from around the year 2000 are failing about now. In 2005 the gaskets were changed to a compatible material. If you have a 2006 or later model year or the engine is a four cylinder, Dexcool is safe for it and is the best choice. If you have a V6 or V8 from 1996-2005 it is not safe and you would be better off with a compatible coolant, like Prestone Exended Life.
Do not mix discount store antifreeze with the factory installed Dexcool. You will plug-up the cooling system if you do! Any GM Dealer will explain this if you ask them.
#1. Make sure the radiator is filled to the top when the engine is stone cold. Fill the plastic coolant recovery reservoir at least 3/4 full at the same time. If the radiator was low go to the next step:
#2. Take the car to a GM Dealer and ask for an inexpensive cooling system pressure test which will find any external or internal cooling system leaks.
#3 If the radiator was full to begin with, you need a new low-coolant solenoid on the left side radiator plastic end tank facing the engine with the hood up.
Prestone Extended life is approved
http://prestone.com/products/print/411?p...
if the manual says dex, use dex or an upspec alternative. Using the wrong coolant in a modern engine can cause all sorts of issues with seals and corrosion.
i suggest Prestone anti freeze coolant
Don't mix coolants.. Flush it out and add normal coolant you'd be fine.
So recently, my low coolant light came on. My car has almost 90,000 miles and it takes dex cool antifreeze according to manual. What shoulf i do?? Add coolant?? Add water? Flush system?? Flush system and replace with regular coolant?? Since i heard dex cool are engine destroyers.... any help will do. Thanks!
