And interestingly, when the GM Pontiac Dealership replaced my LIM, pre-BC, they put in green universal coolant...

The local GM dealership uses both- depending on the warranty of the customer'* car. If it'* under warranty, it gets Dex. If it'* out, it gets mixes-with-any.

also- my mother'* Monte Carlo has a 3100, 45k perfectally-maintained miles, runs dexcool, and its LIM gaskets failed at about 40k.

my grand prix also has the 3100, and has a rather abused 120k on it. It has green coolant, It'* gaskets are original and no leaks in sight, aside from the radiator (caused by hitting a turkey ).

Sorry if that'* how it was read, but it'* not what I meant. I wasn't changing my argument, I was saying it differently in different posts. The only engines that are having this problem are pushrod engines it seems like, and the 3.8 is one of them. I wasn't denying that it wasn't the only engine with the problem, I just didn't repeat the same thing in every post, it was put differently so I can see where the confusion could happen. By the way, I'm scheduled to be getting a coolant flush and the shop I'm going to refuses to put anything in my car other than DEX. The GM dealer told me the same thing.

If you've ever seen the metal surfaces in contact with the gasket on the heads, let alone the problem with the plastic gaskets degrading and leaking, you would be a believer.

I have removed a few engine intake manifolds in my day and I have never seen the corrosion on the iron head mating surfaces around the coolant passages that I saw when I replaced the LIM gasket on my 30 k 3800 engine last month. It was pitted significantly. Looked like a 100 k engine.

I think part of the reason for the plastic gasket was GM'* concern over galvanic corrosion caused by contact of the aluminum LIM with the cast iron heads.

I run Prestone long life in all my vehicles now.

When it comes down to it.. as with any company... the people you and I see are the techs at the shops not the fools that run the company. There aren't too many techs, none that I can find, that won't admit Dex is a problem. Now of course the "big wigs" are going to fight this as it would mean paying out alot of money.

For example: My 96 monte carlo had wiring issues due to placement of the fuse boxes under the hood. Now to illustrate the fact I can walk through my buddies salvage yard and find a least 3 dozen lumina/monte carlos and 99% will have the problem. I can see it, it'* right there in front of me but GM would never admit to this.

The same goes for Dex cool. The people who tear these engines down see the problem, they can replace the gaskets with the same dang thing and only change the antifreeze type and they last longer. That is just simple diagnostics and it shows if I only change one variable, the Dex cool, then its gotta be the Dex cool.

Looks like I'm buying the extended warranty for sure! My 78,000 mile engine probably looks like it'* got 178,000 miles!

I'm guessing that the orange junk inside of the oil caps in every (6+) Grand Prixs I considered buying was Dex then?

After I switch to the Prestone compatible, what'* the maintainance schedule for it (when to flush)? I'm assuming that it won't last the 100,000 miles that the Dex is supposed to?

Nope. 5 years or 100,000 miles. I do mine every 3-4 years.

For the record, my folks 99 Blazer with a 4.3 was just officially diagnosed with leaky intake gaskets. 100k miles, GM dealer says "they all do that around 100k"

Not leaking into the crankcase yet, gonna do something about it when the weather warms up. And refill with green stuff this time.

My '98 SE has 165K miles on it, and I bought it with 160K, so I have no idea if the previous owner had to replace the antifreeze, gaskets, etc. After reading this it scared me half to death so I looked under the hood and sure enough, orange coolant, but it didn't look sludgy or discolored. Now I don't know what to do, the engine runs beautifully!

Just don't wait too long! That'* a disaster waiting to happen. Sooner is much better than later when it comes to this problem, IMO!!

You may be OK. Look in TECHINFO above for the way to read the manufacture date on your upper intake manifold (UIM). In the likely event that yours has already been serviced, the date will be later than the year of your car.

If your car is running well and you are comfortable there are no issues, you are likely right. Just make sure that you regularly review all your fluids for levels, color, and consistency. Any changes warrent a question or two.