To DexCool or not to DexCool? That's the question.

I went to check the fluid level of the radiator on my '98 S-10 pickup and noticed that the water/coolant was black.Yes BLACK.Not brown or orange but BLACK.
I was going to flush the system includind the block but was wanting to know one thing. Should I replace the coolant with Dexcool or can I use standard coolant?
The truck has 168,000 miles on it and going strong.I purchased it with 160,000.When my duh huh ex-mechanic serviced the truck,he never mentioned that coolant. I assume he was tired or in a hurry.
Lat dollar spent there.
Any suggestions on the coolant would be helpful.

P.S. I have read all the good and bad about dexcool and I can't decide.

['97ventureowner]

Did you read this article about Dex Cool? http://free-auto-repair-advice.blogs...label/Dex-Cool
Some good points are made there to continue using Dex Cool as it was specifically designed for your engine and internal parts. Much of the "issues" blamed on Dex Cool has been linked to improper / lack of maintenance of the product. I continue to use Dex Cool in all my GM vehicles in which it came in with no problems, ( The only problem I had was a faulty intake gasket on a 3.4 and this was poor quality gasket material, not the Dex Cool's fault. GM has since issued a revised gasket.) I flush and refill my coolant based on the maintenance schedules for the old ethylene glycol based (green) antifreeze. I'd thoroughly flush out all the old coolant from your engine, making sure you try to get most of it out and refill with Dex Cool and then continue to service it on a regular basis.
One more thing. The old standby green coolant does not offer the same protection packages for your engine as the GM approved coolant Dex Cool.

[silicon212]

Not to mention that the old green antifreeze contains silicates, which can wipe out the bearings on your water pump. Older water pumps were designed to cope with this, newer ones aren't.

[Dr_Rock]

Thanks for posting the link I have been trying to research this issue for the last couple weeks as my car manual says to use the Dex-cool.

[Blue Bowtie]

Originally Posted by '97ventureowner

... I continue to use Dex Cool in all my GM vehicles in which it came in with no problems,

Ditto here. I've even changed over my '86 and '94 to DexCool, and have stopped eating heater cores every two years in the '86. Maintain it properly, and you shouldn't have any problems. Check concentration, pH, and conductivity/TDS once a year, and change the coolant if the numbers get out of spec or it is five years old. It is imperative to keep air out of the system to prevent solids precipitation and the resultant sludge formation that everyone blames on DexCool.

[ZL1power69]

Only problem with the s-series cooling system is that its not air tight and dexcool is suppose to be used in air tight systems. It really needs to be serviced just as often as std green coolant.

[brandon200317]

i have my 96 and haven't had an issue with dex.. i would just go with what is recomended for you vehicle. as for it being black.. have you checked your head gaskets? black coolant could be a sign of oil getting in to the system. my parents just had a 97 astro blow a headgasket and it was dumping alot of coolant into the oil.. needless to say it died for good.(RIP)