Has anyone had any problems related to Dex-Cool in their Cobalt? Do I just need to make sure it is filled up to the proper line in the degas bottle? Should I fill it slightly higher to make sure all of the metal parts are submerged?

 

I've had zero problems, although I'll admit I'll probably get mine flushed and replaced early to prevent any trouble. This is my first car with Dexcool so I'm keeping a close eye on it.

You've probably read or heard about the various issues people have had with 3.1 and 3.4L V6 engines having coolant leaks at the lower intake manifold gaskets; fortunately the Ecotec engines don't have any coolant passages in the intake manifold gasket so this big trouble area is gone.

My belief is that a lot of the Dexcool problems are related to people either adding the wrong coolant, or improper flushing and bleeding that leaves too much air in the system. You know how certain cars are notoriously tricky to burp all the air out of the system? Something that sounds harmless like too much air seems to turn Dexcool into sludge.

I see another thread in this section where people are talking about coolant hoses being dissolved by the Dexcool; it doesn't seem like that issue was fully answered in that thread. Myself, I've noticed no discoloration of the coolant in my car, so maybe it was an isolated problem.

 

I heard from Z06 owners and CTS-V owners that they had zero problems. I thought it was because the Dex-Cool strips metal surfaces of lubricants/corrosion inhibitors, which causes the metal to oxidize. This would be particularly bad in heat exchangers, but I think GM even used the traditional radiators at one time. It looks like the SS/TC uses a degas bottle which ought to keep the fluid level above all metal surfaces. I'd still want to find out how I can keep the system in tip top shape.

 

I suspect some of the problems are also gasket designs, not just the dexcool on it's own, and I had to change a LIM gasket on my GP GTP, it was just destroyed.

 

The original problem with Dexcool (which is the reason for the lawsuits regarding it) was that the aluminum was being eaten away by the dexcool. This only occured on the old V8 and V6 cars (and a few of the 4 cylinders). GM has changed the composition of the aluminum heads and blocks so that the dexcool does not damage them anymore.

If you are worried about using dexcool you can always switch to either the normal green glycol or switch to an OAT antifreeze. The most import thing when switching antifreeze is that ALL the old coolant must be flushed out. If you mix even a small amount of dexcool with another antifreeze it will turn into mush and clog everything up.

As long as you keep the antifreeze level at the mark (checked when the car is cold... which means not driven for at least 2 - 4 hours) on the overflow bottle you are fine. Do not overfill or it will overflow all over the engine bay which can e messy.

 

Mine was underfilled from the factory, enough to set off the low coolant message, lol. Of course, I've been too lazy to top it up too, I should make them do it.