o.k. Thanks will do

HI Shanks, I certainly don't really need to reply here, because "wilwren" has done his usual excellent job with excellent material for you.

Just two things: From my personal experience on three "dexcool victims" of my own, and reviewing those lower intake gasket pictures, that is exactly the mess I found mine in too. (for a minute, I though someone had borrowed my pictures,,,)
Secondly, I have converted all of my (and family members) GM vehicles (including my 2002 GMC 5.3L V- over to the "all compatible, mixed with any color" coolant by Prestone. It looks WAAAAAAAAAAAAAAYYYYYYYY better to me than that "pink poison."

(With appologies to the death-cool manufacturer, as I'm sure if they could "turn back the clock" they would have done things a lot differently.)

Oh, yes, sorry, one more thing: (yeah I know, that makes three things): I have had great success in disconnecting the lower radiator hose to drain.

Good Luck. You have received good advice.

Harry

thanks sorta comical but this will be my third trip to my local parts store to return coolant (Nascar color changing, Now longlast prestone) but if it'll save me trouble I'm all for it... been reading about GM'* new LIM Gasket that i should replace... GM part number 89017816(alluminum gasket?) just gotta find a GM site that sells them ... again Thanks to all as Knowledge Rocks (especially where I'm pretty novice under the hood) EDIT found the techinfo piece on lim gaskets and on where to buy....there'* no way for me to know whether or not i need to replace without taking the lower intake apart other than the date it was manufactured right ? but by the looks of them pics I'll spend the $ before i regret not doing so.... wonder how much labour would cost? as I don't think i'm experienced enough to do the lim myself(although my dad is)

Take a look at where the LIM meets the heads. You should be able to see just a bit of the LIM gaskets. You should be able to tell if your current LIM gaskets are already the aluminums (what year did they start?) or black plastic.

If you have a socket set and a decent torque wrench (and an entire day and a place to work) you can do this job.

You can get the aluminum gaskets at intense-racing.com or zzperformance.com, also.

believe they started in 2006 (aluminum) so my 04'* LIM is probably is prone to failure

JUST TO KEEP THE CONFUSION AWAY THERE IS NO SUCH PRODUCT CALLED: Prestone long life dex cool compatible, there is only: Prestone extended life GM dex cool approved!

I checked the labels on the two bottles by Prestone and noticed they had exactly the same chemicals. Two of them are anticorrosion for the various metals in the cooling system. The bottles didn't note any proprietary, nonexplained other chemicals.

So I called Prestone and got a return call from a tech. He said, "They are functionally the same." I took that to mean they have the same active chemicals in them, period.

Perhaps the question I should have pressed on was whether there were any others in there that weren't listed on the label. That question got me the "functionally" answer.

My bet would be on that they are the same other than color. I'l bet the DexCool formula, which was changed after the early problems were noted, was changed and has been adopted for a more general coolant. The DexCool was acknowledged to be better for anticorrosion protection between the various metals. I'll bet there'* a contact involved that they have to product the DexCool as a separate label product.

As I said elsewhere, I'm tempted to switch to the Mixes with all Colors instead of frequently replacing the DexCool.

Are the '05 Bonnevilles effected by this messed up Dex Cool crap as well? My overflow bottle says Dex Cool on it but not sure if mine has the improved stuff in it or not.

Nice write up Will!!! Got any like this for other known issues.