What to do with DexCool

[KX2000GTP]

I recently bought a 2000 GTP and when i was looking over everything last night i saw that my resevoir contained liquid that looked black. I came to this forum and read a lot of issues concerning DexCool and how it turns to 'mushy brownies' and also where some people have removed the DexCool, flushed and added the Green Stuff. I was planning on doing this so i went and bought two bottles of coolant, a new tstat, and Zerex cooling System Cleaner by Valvoline.

So my questions...

is it a good idea to do the flush and switch, or should i stay with DexCool and just resort to getitng it flushed every 5 years?

If i should flush it, is the ZEREX a good product to use or is there something better?

BTW. the new antifreeze is the "new formula" that supposedly can mix with any color...

I'm new to the forum and to actually doing work on my own car in general, so ANY help is appreciated.

[richtazz]

Take it from a guy who works at a Delco distributor, DEX-COOL SUCKS!!!!! It turns corrosive as it ages, and turns brown and sludgy for no apparent reason. MAke sure you THOROUGHLY flush the system, because Dex-cool and green don't get along. Even though the new green stuff says it won't gel up if combined with Dex-cool, I'd still be extra diligent in flushing the system. All green anti-freeze brands are identical, so go with whatever brand you like.

[KX2000GTP]

This seems to be the general consensus from everyone i've talked to, GM dealers included.

The Zerex says that it should be combined iwth water and driven for 3-6 hours before draining. then flushing with water again(not running) then to add the new coolant. So should i swith tstats before during or after the flushing?

Thanks for the reply so quick. This board so far has been awsome!!

[stlwagon]

Had the same problem with Dexcool in my 99 GTP. Better to catch it early before the sludge starts to gunk up your heater core. I switched back to Prestone and have had no problems. May want to remove the T-stat during the flush process and then replace when adding the new coolant. May want to consider dropping in a new 180 t-stat since you'll have it open anyway.

[KX2000GTP]

Anyone know where to pick up a 180 tstat? I went to Advance and they only had 192/195.

[stlwagon]

www.pfyc.com or intense-racing.com

[richtazz]

unless you drive your car hard, leave the 192/195 in there. It's what your computer is set up for and should cause you no problems unless yu live in the desert and play Racer Rick at every stop light. Definitely change the stat AFTER the flushing is done, to avoid gunk and crap foo-fooing up your new stat

[Bruce123]

Check out this GM service bulletin on procedure for cleaning the cooling system (link originally posted by carnutcass I think).

http://www.geocities.com/b_gillie/TSB990602012.htm

The bulletin is actually for other GM vehicles, but is an excellent tutorial nonetheless. Also, they say to replace the old DexKill w/ new DexKill, but we know better... The key thing is that it is imperative that you get every drop of the orange stuff out before you add the green.

Don't forget to remove and clean the reservoir bottle and its hose, and remember to bleed the air out of the system once you get it all back together.

Also, do replace the radiator cap.

Good luck.