I'm pretty sure the manual says dexcool. So I'm probably going to go with that. I will check again to make sure. Just made me nervous with all the negative reviews on it. But in light of new evidence I'm a lot more confident in it now.

 

Dex is fine. Just don't let it sit for the full 5 years and especially not the 150,000 miles that they say it can sit.

Fluids break down and our blocks are made of iron, keep it flushed about every 3 years and you shouldn't have an issue with it.

 

Gm used the nylon gaskets on the 3100/3400/3800 for years.

Felpro makes metal core replacement gaskets (those are the ones to use when doing the job).

Common signs of failed lim gaskets is loosing coolant and milky looking oil.

 

Thanks Maniac. That is good info to have.

 

No real way to tell without taking the LIM off unless you can somehow look at the edge of the LIM and see the plastic edge of the gasket.

 

If you use a radiator pressure tester you can find if the lim gaskets are bad (you will loose pressure and typically see it bubble along the edges as the pressure escapes).

 

Thanks maniac

 

I switched my '03 to green fluid from death-cool!! lol! I always heard that too from several mechanics, my radiator shop owner said that dex-cool was ok but it did have a corrosive effect on plastic parts,and being an '03 lots of plastic parts are getting wet with it!! he replaced my side caps (plastic) on my radiator cause it was leaking,flushed,rodded,new thermostat,hoses and clamps for 260$ no prob since! he also told me, cause I was gonna but a new radiator as its 14 years old not to cause the original was made better with better metal than the crap you get online,ebay etc?? unless you get a hi perf part or replacement!! jmo!!

 

Thanks Clay. All opinions are welcomed. After further research I went with the Dexcool. Hopefully they got it right with the new formula.

 

Got news for ya, I've had those plastic parts fail on cars that never used dex and had good old green. It's because the plastic/nylon is crap to begin with. Hot fluid with pressure pounding on it plays a toll on over time.

Old dex was found to be corrosive and gm re formulated that I believe before the year 2000.

Keep in mind, gm lost their butts in a class action lawsuit over dex, I doubt they would keep using it if they did not fix the problems.