I'm back. The Monte was heating good. once again the top line to heater core is HOT and lower warm. could this be a waterpump issue????
Flushed all the DEATH cool out. well much as I could. put rad flush in system and ran a day or two. flushed system from lower heater core line to cockpit and then to top of the rad..
Heat was good when she left. new thermo, and coolant. At a loss???

 

FIXED...
Core kept plugging from old DEATH COOL...
the RED DEVIL in solution cleaned her out real good and quick...
Now you can't put heat on high... Runs ya out....

 

I'm not sure why everyone has such an issue with dexcool. It works the best with gm engines. I've never had bad experiences in 13 years as a tech with "the red devil".
Using anything but gm dexcool might lead to a problem, or if you mix it with non distilled water. IMO. Not trying to start any fights.

 

Glad you got it fixed. I think a lot of dex-cool's negativity comes from all the failed LIM gaskets. I know some of the original articles and blogs I read back in late 1999 early 2000 blamed dex-cool for the failure. I think just like ever other fluid in your car you need to change it periodically or it will let you down.

 

Yeah DexCool happened to be "new" when people began noticing large mass quantities of LIM gaskets failing. And as I know, GM revised the Dex formula at one point as they did find evidence the original formula promoted damaging the LIM gaskets.

But, as I've said many a time, the LIM gaskets were a JUNK idea from the get go. It may go further back then '94, but I know the problems with nylon gaskets have existed since '94 in the 3100 up to the present day 3400. My Grand Am since the day I bought it has ran nothing but "good ol' green stuff" (not sure what it had from the factory). I've replaced the nylon LIM gaskets twice now, because the nylon can not hold up to the hot fluid flowing through it. Hence part of the reason companies are now coming to to bat with aluminum LIM gaskets.

 

where can you buy this red devil stuff and what is it

 

dude u dont want to get that s--t trust me what im tellin u.