As C371 has mentioned. If there is an expansion tank doesn't that introduce air. So if Dex-Cool cannot "see" air then how can it allow for an expansion tank.

I just bought a brand new radiator from DeWitts. They recomend Dex-Cool.

 

zwede I think there is more to it than bad intake gasket design. Ford uses the same style gaskets(black plastic with rubber inserts). They don't have near the same amount of gasket failures. They don't even have a quarter of the lower intake failures from what I have seen over the years. If you look at how the intake gasket fails you will see it is always at the coolant port. The plastic is usually deteriorated and broken. The rest of the gasket looks fine. If you want I can snap some pics of one on Monday. I keep a stack of them to show customers.

 

I still think it's more a case of poor material selection by GM than dex-cool. Even though the ford gaskets may look like the same plastic it is very possible they use a different kind that works better. There's also the question of material expansion rates (block/heads/intake) that can stress the plastic carrier.

 

I have even seen the aftermarket ones also do it so I don't think it is material. Plus I would be willing to bet that thw same outside company make both gastes for Ford and GM.

 

exactly what I heard from an engineer. On a totally sealed system, it's fine. But if air gets in andmixes with the DexCool there's a problem.

 

Do yourself a favor and steer clear of Dexcool. It's just not 3.1&3.4 engines that are having problems with Dexcool.
Some of the worst problems were in the S10 Blazer Line with the 4.3 engines. Do a Google search and you'll find a litany of complaints about seized engines and blocks plugged solid with Dexcool.
It's major problem is, it does not tolerate air in the system. A bad radiator cap or water pump seal is all it takes to destroy a motor
By the way, my wife drives a 98 S10 thats how I know about the red sludge curse of Dexcool. I saved her engine by draining, flushing and going green.
Today we have another problem tho and that is the disappearance of regular green glycol. Most mfg are now going to extended life antifreezes and a lot have the same formula as Dexcool so read the container carefully and compare to Dexcool.
The brand I use is Zerex Gl5 which uses a hybrid organic additive technology and was developed for Mercedes/Chrysler. There hasn't been,to my knowledge, any of the issues with the HOAT solutions that have plagued Dexcool
LOL Bob

 

I have a 2001 Impala, 3.4 that develped an intake leak. My brother -in-law runs a local radiator shop and showed me allot of tech information regarding Dex Cool. While the coolant may not be the primary cause, as stated previously, when mixed with air, it causes big problems.
Based on the tech data and my brother-in-law's recommendation, we switched the Impala to green Prestone, 2 years later no issues.
I do think the intake gasket design contributed heavily to the issue, however if you are running any aftermarket aluminum intake against cast iron heads, I would be wary and probably not use Dex Cool.

 

Funny I hit on this. Just rebuilt a '96 vortec 350 (127,000 mi). Both head gaskets and intake manifold were leaking. Head gaskets leaking out, intake leaking in. Just slowly eating antifreeze, no effect on motor. Loss in oil pressure made me rebuild (cam bearings shot). Amazing thing is the coolant passages were pristine. Cast iron had no sludge, no film, no nothin'. Aluminum and plastic had a thin film. Yea, it was always Dexcool. Intake manifold appeared to be installation problem, was not sure of the head gaskets. Now, I'm thinking the corrosive properties of the Dexcool add up to potentially why these gaskets went. Guess what? Got a 2002 Monte Carlo with a manifold leak. I'm thinking no more Dexcool for Dan in GM products. Have had it Chryslers for years, cannot think of any gasket problems with them.

Thanks for the info Dan